Session Index

Understanding the influence of oxygen on cellular functions and behaviors is crucial for investigating various physiological and pathological conditions. In order to study cellular responses under specific oxygen microenvironments, various in vitro cell culture models have been developed. However, precise control of oxygen microenvironments and accurate characterization of the oxygen variations with great spatiotemporal resolutions remain challenging. In this talk, I will discuss the appoarches developed in my lab to control the oxygen microenvironments for cell culture using microfluidic devices, and the oxygen sensing scheme based on frequency-domain fluorescence lifetime imaging microscopy (FD-FLIM) for intra- and inter-cellular oxygen characterization.

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A supercontinuum laser source emitted from an optical fiber is suitable for developing microscopic transmittance spectroscopy. The spatial resolution of the microscopic transmittance spectrum as a function of the optical wavelength, measurement distance, and sample thickness is quantitatively evaluated.

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This article discusses the impact of morphology on the performance of photomultiplication (PM)-type organic photodetectors (OPDs). A non-fullerene acceptor, Y6-Se-HD, is synthesized and used to fabricate PM-OPDs with a broadband spectral range from 320 to 1090 nm. The devices achieve a maximum EQE value of ~6500% at 860 nm at a low bias of −1.0 V. Morphological analysis shows that Y6-Se-HD covers the entire active layer, avoiding direct contact between the hole-trapping donor polymers and the Ag electrode, resulting in stronger charge trapping and preventing charge recombination and/or quenching. This research highlights the importance of morphological effects on PM-OPDs

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A highly sensitive open-cavity FPI gas pressure fiber sensor was proposed with Vernier effect. By using the beveled fiber polishing technology, an open-cavity FPI can be formed. Besides, due to our sensor contains three reflection planes, we can have a sensing FPI and a reference FPI in a compact sensor structure to induce Vernier effect. The measured gas pressure sensing sensitivity is shown to be enhanced to 4.6 times as 133.43pm/psi.

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This paper proposed a liquid-index sensor based on a tapered-fiber Bragg grating whose surrounding liquid-index variation by varying the liquid different concentrations to cause the change of grating reflection spectrum and then to obtain the liquid index.

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A novel small-scale high-sensitivity gas pressure sensor based on a fiber grating is proposed in this paper. The sensing structure is to utilize the plastic material cavity to apply the gas pressure on a thin-metal diaphragm glued on a fiber grating to result in the grating wavelength shift with a nice sensitivity of 0.13642 nm/psi and an excellent repeatability.

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Abstract: We designed and investigated a novel optical biosensor based on a hybrid plasmonic and electrochemical phenomenon. The Surface Plasmon Resonance was generated from a thin layer of gold nanohole array on a glass substrate. Using C-Reactive Protein (CRP) as the target analyte, we tested our device for different concentrations and observed the optical response under various voltage bias conditions. We observed that SPR response is concentration-dependent and can be modulated by varying DC voltages or AC bias frequencies. For CRP concentrations ranging from 1 to 1000 μg/mL, we obtained a limit of detection for this device of 16.5 ng/mL.


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A sandwich-type immunoassay for simultaneous detection of low-concentration of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) was developed by integrating two types of upconversion nanoparticles (UCNPs) with a low refractive index resonant waveguide grating (RWG). Under resonant excitation, the local electric field is enhanced atop the RWG leading to extremely high intensity of UCL, resulting in improving the detection sensitivity of the immuno-biosensor. The limit of detection of the biosensor is 0.76 fg·mL-1 for cTnI, and 0.98 fg·mL-1 for NT-proBNP, much lower than the serum cut-off value of 30 pg·mL-1 for cTnI and 450 pg·mL-1 for NT-proBNP.

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Traditional Shack-Hartmann wavefront sensors are typically constructed with bulky components, resulting in their weight and the occurrence of chromatic aberration. In contrast, utilizing a metalens not only reduces the physical size but also eliminates chromatic aberration, making it suitable for multi-wavelength wavefront sensing. In this work, we developed a multi-wavelength metalens capable of simultaneously operating at three different wavelengths for compact wavefront sensor application.

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In this study, we designed a split-ring resonator metamaterial for gas sensing of the nitric oxide (NO) in the terahertz frequency range (resonating at 0.257 THz). To further enhance gas absorption, a thin film composed of ZnTiO3 and reduced graphene oxide (rGO) was applied on the surface of the metamaterial. By sintering ZnTiO3 powder at various temperatures, the sensitivity of this device (ΔT/T) was successfully increased from 2% to 16.4%. This material holds promising potential for future developments in monitoring and wearable devices.

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Peripheral blood phosphorylated Tau (p-Tau) protein is one potential biomarker of Alzheimer disease detection. However, the concentration of p-Tau in bloodstream is extremely low (0.09 pg/mL). Tm3+-doped upconversion nanoparticle (Tm3+-UCNP) has fascinating upconversion luminescence (UCL) properties and be utilized to biosensing, usually sub nano-molar level. Here we proposed a low-refractive index resonance waveguide grating (low-RWG) array chip, which integrated 793 nm laser that significantly enhanced Tm3+-UCNP immunosensing to sub femto-molar level. Results showing extremely low limit of detection (LOD) of 0.57 fg/mL. A model study of immunosensor targeting p-Tau181 on the low-n RWG chip is proposed.

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The traditional SPR biosensor uses two-dimensional materials to enhance the sensitivity, but the time is too long to immobilize material enhanced sensitivity on the chip quickly, and a linker is required. Usually linker is a modified functional group between metal and two-dimensional sensing material. The whole process performance is low. In this experiment, graphene is mixed with toner and printed directly on copper foil with a laser printer. The results show that get more obvious character of graphene after printing, which provides a fast and high performance method for immobilized biosensors.

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This study presents a photothermal fiber Fabry–Pérot interferometer (PTFFPI) that is fabricated by a polymer mixed submicron metal particles (PSMP). The proposed PTFFPI-PSMP was heated by a LD with a wavelength of 980nm and an excellent photothermal characteristic was achieved. Based on the experimental results, the device can be successfully heated by laser due to absorption improvement by the polymer mixed metal particles. The LD heating process can achieve a steady-state high temperature (T) to shift the interference wavelength fringes of the PTFFPI-PSMP. Due to the high thermal expansion of polymer, the proposed PTFFPI-PSMP can have a high sensitivity.

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Ultrafast lasers concentrate the energy with a duration of several tens to hundreds of femtoseconds. In practical applications, the optical dispersion broadens the laser pulse width and spreads the energy in time, thereby reducing the peak power. Accordingly, the present study develops a piezo bender-based pulse compressor to compensate for this dispersion effect and restore the laser pulse width. Due to hysteresis and creep effects, the piezo bender is unable to maintain a stable shape over time and the compensation effect is gradually degraded. So, this study further proposes a single-shot modified laterally sampled laser interferometer to solve this problem.

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We developed an ultra-short cavity hollow-core fiber (HCF) Fabry–Pérot Interferometer (HCFFPI) based on splicing a tilted HCF to achieve the measurement of thermo-optic coefficient (TOC) of liquids. Based on fusion splicing an extremely short section (<10um) of slant cleaving HCF between two fibers, a very tiny gap can be formed to ensure that the liquids can flow into the short cavity. The TOCs of DI water, Ethanol, and Cargille liquid (nD=1.33) can be accurately determined by the proposed approach to predict it would have a great advantage for effectively and precisely measuring optical parameters of liquids in picoliters volume.


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In our experiment, we designed a Schottky barrier surface plasmon resonance sensor based on a metal-dielectric-metal structure. The Schottky barrier filters out the noise and improves the sensor design. We established the device fabrication process, including design, debugging, and fabrication, the measurement system, and conducted device testing. Additionally, we analyzed and compared the I-V curves of fabricated and standard samples. Furthermore, the optical characteristics under various incident angles are simulated and measured to demonstrate the surface plasmon resonance (SPR) effects.

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We utilize a semiconductor laser with optical feedback to generate chaos waveforms with broad-bandwidths for lidar applications. By calculating the lags difference through cross-correlation functions, we establish a correlation-based chaos LiDAR system. We study the bandwidth and signal-to-noise ratio and, their impact on the ranging precision. We find that, with the broad-bandwidth waveforms, LiDAR system with higher precision and exceptional anti-interference capabilities can be simultaneously achieved.

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This study introduces a novel step-attached guard ring structure to address edge breakdown effects in InGaAs/InP planar avalanche photodiodes. This innovative approach reduces the edge electric field up to 10.5% and confines breakdown occurrences to the center of the multiplication area.

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A silicon-based device fabricated using Schottky barrier demonstrates that different structural designs modify the surface plasmon resonance, resulting in varying resonance intensity and spatial distribution of the electric field. By hot-carrier diffusion, this device achieves a better infrared light response and amplifies specific wavelength of signals. The device with the newly-designed microstructure exhibits a 2.14-fold enhancement effect with the incident light at 5.3 µm under the same incident light intensities.

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In this paper, we propose a novel fiber optic pressure sensor using a fiber grating
combining with a special packaging structure. Its working principle is based on the fact that
the grating wavelength shift is proportional to the applied pressure, and a fiber grating etching
process is used to increase the sensitivity of the sensor.

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In this work, we prepare cesium lead bromide (CsPbBr3) nanoplatelets (NPLs) by the co-precipitation (CPT) method, which is a simple route to mass-produce nanocrystals under ambient condition. By regulating the molar ration between Cs- and Pb-based precursor, the colloidal CsPbBr3 NPLs are successfully synthesized. Subsequently, the CsPbBr3 NPLs are redispersed in toluene to form a colloidal solution for ultrasonic spray-coating of perovskite film as an X-ray scintillator, whose thickness is well-controlled by the spray-coating cycles. Eventually, a CsPbBr3 perovskite film with a thickness of 553 μm is fabricated to deliver a high X-ray induced radioluminescence.

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Due to the rapid decay characteristics of hot carriers, this study discusses the excitation positions of hot carriers in silicon-based (Si-based) photodetectors to bring the excited carriers closer to the metal/semiconductor interface. This approach aims to increase the injection efficiency of hot carriers, thereby enhancing the responsivity of the photodetector in the mid-infrared (MIR) region.

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Fibre Bragg gratings (FBGs) are well-established all-fibre devices capable of monitoring a range of parameters in various configurations with high precision incl., strain, temperature, and pressure. Due to the ability to accurately design the phase and amplitude response from FBGs into their spatial refractive index profile, and because of the flexibility to precisely control their length, they can also be used as devices to help correct signal distortion encountered in optical transmission systems resulting from, for example, timing- jitter and chromatic dispersion. The precise control of length can also be utilised to monitor and determine perturbations continuously along their length, in real-time. One such application, demonstrated and researched more extensively in recent years, is the ability to monitor and determine the velocity of rapid chemical reactions and detonation events with a very high degree of spatial precision.

The speed at which shock-fronts advance through a material – the velocity of reaction/detonation – is an important measure for assessing the performance and characteristic behaviour of the material. Optical fibre sensors, incl., FBGs, are proving an excellent diagnostic tool for this purpose too, and because of their small size, they can be used as embedded probes offering minimal physical invasiveness into the compounds and materials being tested. In this talk we will review and discuss our research in this area and discuss probes based on both uniform and chirped FBGs, bare fibres, and rare-earth doped fibres. We will discuss how these probes are designed and discuss the advantages and limitations of each of them depending on the exact application and system they are designed for. We will show that using a new approach we developed based on uniform FBGs it is possible to achieve spatial uncertainties below ±10m when determining the position of the perturbation on the FBGs during high-speed events with velocities in excess of ~6mm/s (6km/s).

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Scattering is the most common phenomenon in optics, but it has not been widely adopted in online real-time scenarios. In view of the potential for real-time intelligent scattering detection, this paper proposes a conceptual structured light scattering detection device.

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An epilayer of Zinc Gallium oxide with a thickness of 100 nm was successfully grown on a c-plane sapphire substrate using the metalorganic chemical vapor deposition technique. The performance of the designed photodetectors was evaluated by measuring the photocurrent under various bias voltages and distinct x ray flux intensities: ranging from 107 to 1011 counts per sec. Additionally, the transient response of the photodetector was examined. The findings revealed that these designed photodetectors exhibited higher sensitivity compared to detectors based on gallium oxide.

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We demonstrated neoteric point of care fulfilling waveguide nanogold linked immunosorbent assay optical biosensor to endow ultra-sensitive and prompt detection of crucial biomarkers such as Procalcitonin. The proposed sensor reveals excellent biosensing performance with a negligible low non-specific adsorption, low record LOD of value 48.7 fg/mL and short detection time of nearly 9 minutes.

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This study focuses on generating random modulated pulses using a gain-switched semiconductor laser with a recirculating delay lines (RDL) interferometer designed for pulsed lidar application. The RDL structure's multi-interference bestows the random modulate pulse with high modulation and low-correlation characteristics, well-suitable for pulsed lidar unambiguity ranging and jamming resistance. By adjusting laser bias currents and RDL delay lengths, we assess two distinct scenarios: one optimizing precision for 3D reconstruction, and another emphasizing low correlation for anti-jamming. Finally, we successfully demonstrate 3D imaging, showcasing exceptional precision in capturing intricate detail, such as the Marseille statue.

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Photomultiple narrowband organic photodiodes (PM-NOPDs) are fabricated using a
planar heterojunction structure. The bottom PM6 layer selects excitons, while the top P3HT: PC70BM layer acts as a photomultiplication layer. The device functions with electron tunneling injection caused by hole accumulation near the Ag electrode. Because only selected exciton undergoes photomultiplication, the detector exhibits a high external quantum efficiency of 5840%, a narrowband peak at 680 nm, and a spectral response of over 30 A/W at -5 V. This approach allows for the fabrication of high-performance PM-NOPDs with low bias, low noise, and high speed.

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Guided mode resonance (GMR) gratings are gaining traction in sensing applications. This study outlines an optimal, easy-to-fabricate one-dimensional GMR grating with enhanced performance using thin films. Its design boosts the sensing performance with figure of merit values reaching hundreds of thousands. Simulations show an optimized grating with a sensitivity of 252 and a narrow bandwidth of 0.0002 nm. Remarkably, at a 50° incident angle, its figure of merit reaches 839,666, outperforming traditional GMR sensors significantly. Simulations at 60° and 70° incident angles expand its applicability, offering insights into the sensor's varied performance scenarios.

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In this article, the integration of the brillouin optical time-domain analysis (BOTDA) and the phase-sensitive optical time domain reflectometry (Ф-OTDR) distributed fiber sensing systems is discussed. By combining the two systems and sharing common instruments, the cost of the experiments is minimized, enabling the sensing of three parameters: temperature, strain, and vibration on the same 18.7 km fiber.

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Various Al atomic contents were doped into HfGaO and were deposited on sapphire substrates at approximately 80 K by using a vapor cooling condensation system. By using energy-dispersive spectrometer measurements, it was found that the Al atomic content in the AlHfGaO films increased with an increase of the deposition temperature of an Al2O3-powder- loaded tungsten boat. AlHfGaO films with an Al atomic content of 3.16% had a higher optical bandgap energy (5.36 eV) than did undoped HfGaO films (5.14 eV). Increasing the Al atomic content reduced the Ga atomic content; however, the Hf atomic content was similarly unchanged, which revealed that the Al dopants substituted Ga atoms. By using X-ray photoelectron spectroscopy measurements, it indicated that the oxygen vacancy defects in HfGaO films were suppressed by doping with Al to produce AlHfGaO films. These results verified that the Al doping of HfGaO films could effectively modify the bandgap energy and could suppress oxygen vacancy defects.

The AlHfGaO films with various Al atomic contents were used as the channel layers of ultraviolet phototransistors. The undesired oxygen vacancy defects residing in the AlHfGaO films could be compensated and suppressed by doping Al dopants. In addition to modulate the cutoff wavelength of the ultraviolet phototransistors by doping various Al atomic contents in the AlHfGaO channel layers, the performances of the resulting phototransistors could be improved due to the reduction of the amount of oxygen vacancy defects. Compared with the phototransistors using the HfGaO channel layer, when the phototransistors using the AlHfGaO channel layer with an Al atomic content of 3.16%, its cutoff wavelength was shifted from 240 to 225 nm, and the detectivity was improved from 1.62 × 1012 to 3.16 × 1012 Jones. Besides, the photoresponse speed was also improved by increasing Al atomic content in the AlHfGaO channel layer of the phototransistors.

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we demonstrate a spectral-phase SPR imaging sensor. It probes the sensitive phase response at plasmonic resonance with stable spectral SPR image. In our design, surface plasmon excitation is placed inside a polarizer cavity with perpendicular polarization orientation. At resonance wavelengths, the phase related polarization orientation allows light to leave the polarizer cavity, which produces corresponding spectral profile at SPR image. In refractive index measurements, the sensor detected different concentrations of NaCl solutions and the sensor resolution was 8.4 x 10-6 RIU. The spectral-phase SPR imaging sensor can find potential applications in biosensing, chemical sensing and drug discovery.

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A Mach-Zehnder direction coupler with a 50:50 splitting ratio in a silicon platform
demonstrates frequency-modulated continuous wave (FMCW) characterizations in velocity and
distance through Hilbert transform resampling. The measurement speed is 200 mm/second with
a 0.2 mm/second standard deviation. The final most extended detection range can demonstrate
1052.5 cm distance with a standard deviation of 0.006 cm and a full width at half maximum
(FWHM) of 0.0043 cm using 1.25 mega-sample-rate data acquisition.

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This paper presents a fiber Bragg grating vibration sensor for tuning guitars to analyze the variations in non-stationary signals using fast Fourier transform (FFT) and continuous wavelet transform (CWT).

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The contrast or signal-to-noise ratio (SNR) the most crucial and fundamental parameter in an optical sensing system. It’s immediately related with the quality of sensing. In an imaging system, with
a better image contrast/SNR, the imaging system can be performed at a faster frame rate or
deeper tissue locations without compromising image quality.
In this talk, the recent studies of our group on the contrast enhancement in femtosecond laser
based optical sensing/imaging systems will be presented by the higher-order-modulations or the
carrier pulse-stretching. These optical or electrical-optical methods will largely enhance the contrast in the coherent and in-coherent nonlinear laser scanning microscopes. Significant background reduction together with the SNR enhancement will presented in the second-harmonic generation microscopy on collagen fibrils or the two-photon fluorescence microscopy on whole drosophila brains.The fundamental working principles, experimental design, various results on the
femtosecond sensing with enhanced contrast, and the future perspective/possibility for these
technique will be also presented.

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An aluminum-doped gallium oxide (Ga2O3:Al) active layer of metal-semiconductor-metal ultraviolet C photodetectors (MSM UVC-PDs) was deposited by a plasma-enhanced atomic layer deposition (PE-ALD) system. Compared with the Ga–O bond, the Al–O bond was more easily formed, which suppressed the generation of oxygen vacancies in the Ga2O3:Al films. Accordingly, under bias of 10 V, the optimal performance of the resulting UVC-PDs with Al content of 1.88 at.% could be achieved to photocurrent/dark current ratio of 7.8×10^4, responsivity of 0.5 A/W, UV-VIS rejection ratio of 3.6×10^5, and the detectivity of 8.3×10^13 Jones.

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In this work, we present an effect of polarization on the machine-learned, speckle pattern-based Laguerre Gaussian (LG) beam classification. Specifically, four different polarization states are explored namely, linear +45, linear +135, right circular, and left circular; and their effect on the classification performance of a simple machine learning model. The classification accuracies >80% are achieved for each polarization state corresponding to different LG modes. This proves the efficacy of machine learning models for recognizing the speckle patterns of LG modes which are polarization encoded and might be useful in real-world applications for efficient OAM beam multiplexing in free space communication.

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This work developed the colorimetric change optical CO2 sensor using the pH indicator phenol red and
CdSe/ZnS quantum dots embedded in polymer matrix. All of the sensing film materials are coated on the surface
of filter paper. Meanwhile, from the investigation of emission spectra exposed of CdSe/ZnS quantum dots will
increase as the CO2 concentration increased. The experiment results show the optical CO2 sensor has a
sensitivity of 1.8 and it can be applied to environmental applications.

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This study introduces a quasi-optical system developed for material characterization. The system, based on the quasi-optical principle, is operated using a Vector Network Analyzer (VNA). We successfully measured the optical properties of various plastic plates in the millimeter-wave region, specifically from 8 GHz to 12 GHz. The experimental results have been compared with existing data to validate the accuracy and efficacy of the proposed quasi-optical system.

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This work demonstrates a simple approach for the direct synthesis of gold nanoparticles (AuNPs) through photoreduction and the self-assembly of AuNPs on APTES-functionalized surfaces as the substrates for surface-enhanced Raman spectroscopy. We investigated the impact of various reduction parameters, as well as different sizes of AuNPs, on the optical behavior of the Raman intensity. Finally, we applied the SERS substrates to detect MG and biomolecular. Our approach not only involves simple processing steps but is also cost-effective, allowing for the production of more than tens of samples at once.

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This study demonstrates a simple approach for the detection of polystyrene microplastics using Raman spectroscopy. This method involves utilizing compact monolayer polystyrene nanospheres to create an inverted pyramid structure. The SERS (surface-enhanced Raman spectroscopy) substrates were fabricated through nanoimprint and deposition of a gold film using electron beam evaporation. Various SERS sensing approaches to enhance the Raman signal were explored. This study offers a simple and mass-produced method for the detection of microplastics.

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This study develops a fiber-optic sensor based on dual nanoplasmonic structures for refractive index sensing by a CO2 laser engraving. Gold sphere nanoparticles and silver sphere modified the sensor based on dual nanoplasmonic structures in two different fiber sensing zones. This type of sensor has shown the capacity to simultaneously sense two different channels of localized surface plasmon resonance signals with a relatively high refractive index sensitivity.

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In this study, the 10 nm silver (Ag) was deposited with various deposition rate to investigate the coverage area and the photoelectric response of the silicon-based (Si-based) photodetector at 3.46 µm mid-infrared (MIR) wavelength. However, the response voltage was increased from 0.22 V to 0.88 V (i.e. 4 times enhanced) while the deposition rate reduced. The illuminated area of the metal layer increased when 10 nm Ag deposited at deposition rate 0.1 Å/s, which could generate more hot carriers emitted from metal to semiconductor by the internal photoemission absorption (IPA) mechanism to cause the response voltage enlarged.

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A disposable PEN based container was fabricated successfully for the liquid concentration variation measurement in a common path heterodyne interferometer. The best measurement resolutions of saline concentration and RI variations are 48 ppm and 8.7×10-6 RIU, respectively.

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An optical depth sensing was developed in this study. This system is combined with Galileo telescope, micro-lens array, and sensor. The system has been verified its feasibility in the experiment and has the merits of easy to operate and not easily disturbed by external factors and is suitable for combining with various mobile phone lenses.

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The guided modes of elliptical-tube cladding structure hollow-core fibers with different core diameters, thicknesses, and shapes of capillaries for capillary cladding designs by simulation are presented. The proper number of negative curvature ratios enhances fundamental mode power and the 8-capillary dual-elliptical cladding of NC-HCF is better than the single-elliptical capillary for transmission power.

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Michelson interferometer (MI) sensor is a highly sensitive and versatile device with extensive applications in optics, fiber communications, temperature sensing, pressure sensing, gas detection, acceleration sensing, and optical signal modulation. However, traditional hardware demodulation techniques are subject to several limitations. In this paper, Using the deep learning model as a demodulation device for Michelson interferometer-based fiber optic signals without the need for complex demodulation circuits. After training and validating the Pix2Pix (P2P) GAN on a large dataset of source images and target vibration signals, the trained P2P GAN model can be used to demodulate vibration signals from the interference signal.

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Fiber-optic hydrophones are widely used in marine science, military activities, and energy exploration due to their high sensitivity, immunity to electromagnetic interference, and ease of array formation. In recent years, low-frequency detection has become an important research subject for modern fiber-optic hydrophones. In this paper, we design an air-backed mandrel fiber-optic hydrophone and use COMSOL simulation software to investigate its acoustic pressure frequency response in underwater environment. The hydrophone achieves a sensitivity of -136dB (re rad/μPa) with a 3-dB frequency response from 1Hz to 1kHz

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We present a novel all-fiber Mach-Zehnder Interferometer (MZI) sensor developed by splicing hollow-core optical fiber (HOF) between two single-mode fibers (SMF). Utilizing dip coating and electrostatic self-assembly techniques, the fiber MZI was transformed into a metal ion-sensitive sensor. By adjusting the pH values of Chitosan (CS) and Polyacrylic acid (PAA) in the layer coating, we tuned its refractive index and observed distinct responses and variations to copper ions based on different pH values. This all-fiber MZI sensor demonstrates promising potential for diverse metal ion detection applications.

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We introduce an advanced optical design, chromatic confocal microscope with nanoscale optical sensitivity, dedicated to examining the spatial distribution of ions inside optical devices. The ions within organic films present in light-emitting electrochemical cells was utilized as a demonstration example. This innovative approach not only enhances our understanding of ion behaviors in such films but also can be applied to studies involving Li-ion batteries and micro-fluid channels, providing a versatile tool for various research arenas to delve deeper into the intricacies of ion interactions and movements.

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A novel fiber hydrophone is proposed for detecting acoustic-wave signals of underwater. The hydrophone consists of fiber Bragg grating, silicon thin-film, O-ring, and 3D print packaging-structure. The acoustic signal is obtained by means of a photodetector to transform the optical signal of grating-wavelength shift into the electronic signal.

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This report is to investigate the potential of using high-k gate stack MOS for UV image sensors (hereafter HKMOSUVS) with UV transparent high-k gate stack dielectrics and nanocrystalline conductive gates. We investigate the UV-induced inversion capacity CG measured at the low frequency (LF) capacitance-voltage curve of HKMOSUVS. By adjusting the LF, the HKMOSUVS's sensitivity can be modulated for both small and large signals. ITO gate conductor post-annealing process is used to optimize UV optical transmission. Overall, the use of HKMOSUVS with UV transparent nanocrystalline materials has the potential to the development of superior speed, sensitivity, and resolution UV image sensors.

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In this work, we fabricate an optically-switchable light valve based on a liquid crystal (LC) cell integrated with a perovskite (PSK) photoactive film. The transmittance of LC/PSK cell can be modulated by the green laser beam without bias voltage via the light-induced thermal effect. The absorption of PSK film by the illumination of green laser results in heat, which affects the phase retardation of LC layer and the resultant transmittance of LC/PSK cell.

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This study addresses a critical gap in plasmonic surface lattice resonances (SLRs), which have traditionally been limited to longer wavelengths in the visible and near-infrared spectra. We introduce simple yet effective designs optimized for the blue-to-UV range. By leveraging Fabry-Perot mode amplifications and utilizing cost-effective spheroidal aluminum nanoarrays, we theoretically achieve a 42.3-fold increase in Q-factor at a wavelength of 403 nm. This Q-factor is tunable through adjustments to the superstrate cladding thickness. Comparative analyses demonstrate that our designs excel in blue-to-UV wavelengths, enabling higher-resolution biomolecular detection with smaller cross-sections and thereby broadening the empirical utility of SLRs.

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The n-β-Ga2O3/p-Si heterojunction deep ultraviolet (DUV) photodetectors were successfully fabricated by using RF magnetron sputtering. Optoelectronic properties were studied at various annealing temperatures. Improved crystalline quality was observed with higher annealing temperatures, particularly over 700 °C for β-Ga2O3 (110) phase. The device annealed at 900 °C exhibited the lowest oxygen vacancies. The device annealed at 800 °C showed optimal performance in terms of photo current, dark current, and responsivity.

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We successfully developed a novel responsive polymer cholesteric liquid crystal interpenetrating polymer network (PCLCIPN) film with controlled porosity, serving as an optical sensor. Its capability to differentiate between methanol and ethanol in alcohol solutions was examined. By observing wavelength shifts in the transmission spectrum at various alcohol concentrations, the optical sensing performance of PCLCIPN was assessed. The central wavelength changes in the PCLCIPN transmission spectrum allowed for accurate discrimination of alcohol concentrations. Notably, the wavelength shift demonstrated a linear relationship with alcohol concentration, enabling precise quantitative analysis of the alcohol solutions.

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X-ray detection is a highly important detection in the medical field. In this research, we use the non-toxic metal element bismuth (Bi) to replace the lead element (Pb), then choose cesium bismuth halide perovskite derivative, combining the ambient large-area spray-coating to deposit the active layer for the X-ray detector. In this study, we use different process temperatures, two-step heating process, and annealing process to explore the film growth mechanism and measure the electrical properties under various considerations, then verify the influences of the preferred orientation of crystal planes on the electrical properties of the device.

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Machine learning (ML) is a powerful tool that can be used to drive innovation and applications in flexible electronics. ML can be used to design new materials, develop new manufacturing processes, and optimize the performance of flexible electronic devices. ML has been used to develop new types of flexible displays, batteries, and sensors. ML has also been used to develop new manufacturing processes for flexible electronics that are faster, more efficient, and more affordable. As a result of these advances, flexible electronics are becoming increasingly common in a wide range of applications, including wearable devices, smartphones, and medical devices.

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In this study, we investigated the potential of porous silicon (PSi) as a material for detecting the chirality and optical activity of organic molecules through its unique anisotropic photoluminescence (PL) properties. We systematically examined the anisotropic PL response of PSi to chiral and spiropyran molecules with different chemical structures and determined their chiral resolution and optical activity by measuring the polarization and intensity of the anisotropic PL. Our results showed that the use of an improved LED light source provided a higher resolution for chiral structures and significantly improved the discrimination of chiral molecules.

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We developed a facile method for the detection of high mobility group box 1 (HMGB1) using carboxymethyl dextran (CM-dextran) as a bridge molecule modified on the surface of gold nanoparticles combined with a fiber optic localized surface plasmon resonance (FOLSPR) biosensor. Under optimal conditions, the results showed that the FOLSPR sensor detected HMGB1 with a wide linear range , fast response (< 10 min), and a low detection limit of 43 pg/mL and high correlation coefficient values (R^2 = 0.998). Therefore, the present strategy provides a novel and convenient method for chemical and biochemical quantification and determination.

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The local-field enhancement of the plasmonic resonances has been shown to amplify the typically weak vibrational signals from few molecules. However, until recently high-Q dielectric counterparts were employed as an alternative approach. Here, we further explore this direction by numerically studying surface-enhanced infrared spectroscopy with photonic crystal guided resonance (PCGR) microcavities. We show that coupling to a PCGR can lead to EIA-like enlarged infrared absorption of a deep-subwavelength-thick molecular layer by more than an order of magnitude.

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We propose a Fabry-Pérot interferometer (FPI) fiber pressure sensor formed by fiber splicing and vertical polishing technology. As the thickness of the single-mode fiber (SMF) is less than 1 μm, our sensor shows good sensing property to the environmental gas pressure. To improve the sensing sensitivity, we employ the Vernier effect induced by two parallel FPIs with similar cavity lengths. The maximum pressure sensitivity can be as high as 38.5 pm/psi with the magnification factor is about 12. Besides, the measured temperature sensitivity is 16.7 pm/℃.

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This paper presents a LMR (Lossy Mode Resonance) sensor based on a SOI (silicon-on-insulator) substrate, which finds applications in biomedical, chemical, and industrial sensing. The design utilizes the principle of multilayer thin-film reflection, where a silicon waveguide is grown on the SOI substrate and coated with an ITO (Indium Tin Oxide) thin film to form the LMR sensor. By optimizing the thickness of the components, the LMR sensor achieves a resonant wavelength of 0.857 µm and a sensitivity of 0.75 µm/RIU.

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This article demonstrates the possibility of using wavelength-division multiplexing and polarization-division multiplexing to power-supply temperature sensors. The advantages of fiber-optic polarization sensors are their light weight, inertness, and the absence of electricity, which make them suitable for use in environments with a high possibility of an explosion. Polarization multiplexing increases the capacity of existing single-mode routes and allows the simultaneous power supply of the sensor and data transmission on one wavelength. The sensor’s sensitivity was tested by applying a container at different temperatures and by pendulum swinging. The results were evaluated by an optical power meter and a polarimeter.

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Organic photodetector (OPD) using ZnPc:C60 as an active layer is potential absorb the red visible region. However, previous research using ZnPc:C60 as an active layer shows low detectivity. In this study, we optimize the OPD with dual electron blocking layer (EBL) using ZnPc:C60 as an active layer to enhance the detectivity.

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Broadband ultrashort pulse laser characterization and compensation is required to develop the nonlinear optical application. In this paper we have integrated the optical dispersion characterization and optimization based on 4-f linear deformable mirror (LDM) pulse shaper and spatial spectral interferometry (SSI). The dispersion optimization with system identification (ID) algorithm based on Legendre polynomial could achueve up to 7 order Legendre mode, which provide a high-order dispersion modulation ability. We also show the dispersion identification with ResNet neural network model. The predict result with control voltage of LDM also shows a great agreement with ID result.

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This work reveals Néel ordering transformation in MnPS3. In antiferromagnetic (AFM) state, the ordered spin in 3d orbital of Mn2+ cation influences the intrinsic lattice and vibrational properties of MnPS3. The band-edge excitons of MnPS3 were detected via micro-thermoreflectance (μTR) measurements. With T

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In this work, we investigated the electrical properties of indium-tin-oxide (ITO) thin film with transmissive terahertz (THz) time-domain spectroscopy. The ITO thin film is prepared through e-gun evaporation technique on 0.5mm thick glass, whose thickness is 100nm. Through investigation by ultrafast broadband THz pulses, the complex dielectric dispersion relation can be determined. Electrical property such as sheet resistivity is estimated though fitting the dielectric constant to the Drude model, predicted as 29.9 Ω/sq. Results were in good accordance with that obtained from mature yet destructive methods.

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Here we reported the three-dimensional (3D) porous AuAgMEN with plasmonic-active nanostructures provide a high sensitivity to virus detection via the remarkable SERS signal collection. Moreover, the variant-specific antibody-functionalization on the SERS-active AuAgMEN enabled the high selectivity of the SARS-CoV-2 S variants, including wild-type, Alpha, Delta, and Omicron, under the simulated human saliva conditions. The exceptional ultrahigh sensitivity of our SERS biosensor was demonstrated via SARS-CoV-2 S and N proteins , respectively. Our work demonstrates a versatile SERS-based detection platform can be applied for the ultrasensitive detection of virus variants, infectious diseases, and cancer biomarkers.

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Surface-enhanced Raman spectroscopy (SERS) is an indispensable sensing technology in chemical as well as health sectors for its unparalleled capability of detecting Raman-active molecules accurately. Here, we have investigated on the detection of several neurotransmitters such as dopamine, gamma aminobutyric acid and acetylcholine chloride at the concentration of 10-4 M using a metal-based novel SERS substrate following a simple fabrication method. The results revealed that the above-mentioned analyte molecules can be detected unequivocally using the proposed SERS substrate. This study paves a way to detect Raman-active molecules using a cost-effective, unsophisticated SERS substrate.

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This research aims to develop a detection system integrating surface plasmon resonance and Raman spectroscopy. As an example, the feasibility of enhancement of the Raman signal by the perturbation of surface plasmon polaritons is demonstrated by heparin-platelet factor 4 complex. Our results showed that lower concentrations of analysis could be measured and confirmed that the Raman scattering signal would be enhanced at the resonance angle, which is verifying the feasibility of the system. Besides, we also found when the angle of incidence is less than the critical angle, the measured spectrum can be regarded as a general spectrum measurement result.

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Landslide monitoring necessitates timely and precise detection of curvature. Drawbacks like low sensitivity, high noise, and intricate setups hamper the conventional Mach-Zehnder Interferometer (MZI) method for curvature detection. This study introduces an innovative approach, the Randomized Convolutional Kernel of the Mach-Zehnder Interferometer (RaCK-MZI), tailored for highly accurate curvature detection. Remarkably, our approach attains 100% accuracy in training and validation and 98.75% in testing for curvature sensing. This method stands as a notable advancement in landslide monitoring and disaster management. As part of future research, we aim to deploy our technique on a single on-chip device.

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In this paper, a polarization interferometer was proposed to measure the full-field refractive index. This apparatus is designed based on the concept of Twyman-Green interferometer, so it has the advantages of simple structure, easy operation and high accuracy. In the experiment, a BK7 plate glass and a quartz glass have been used to verify the feasibility of this method, and the measurement error can be controlled within 2%.

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The surface spectral reflectance recovery was experimentally investigated using incandescent lamps and synthetic white lamps, respectively. Two ColorCheckers were used as samples. Sample images were captured with a camera. The results show that the experimental results agree with the stimulation results well. The mean root mean square error of the spectral reflectance recovered using incandescent lamps is lower than that of synthetic white lamps.

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This study focuses on the simulation and measurement of infrared absorption of microplastics. The measuring configuration consists of an infrared light source, a collimating lens, the sample in a cuvette, a focusing lens and a detector. The tested samples includes different numbers of microplastic spheres in air and in water. Moreover, an optical simulation software ASAP is used to simulate the optical measurements. When 1000 microplastics are immersed in water, the change in transmitted intensity is measured to be approximately 23%. The simulated value for the same setup is around 26%. The experimental and simulated results are highly consistent.

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We demonstrated a custom-built phosphorescence and fluorescence lifetime system, which featured measuring range from 0.1 ns to 5 μs, and temporal resolving power of <0.1 ns. In order to achieve the selected temporal range of lifetime measurement, we performed multi-frequency harmonics excitation to the luminescence materials. The homodyning system included a FPGA card which provided fundamental frequency to modulate the PMT, and chosen harmonics for LEDs modulation. As high-power multi-die LEDs were used, simultaneous and alternative measurements of phosphorescence and fluorescence lifetimes were made possible. This system might contribute to the study of advanced luminescence device and complex biomedical systems.

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A single layer of amorphous InWO is chosen as the channel material for a thin film transistor (TFT)-based driver and sensing layer for a blue-light sensor, respectively, with a completely compatible process integrated into in-cell embedded photo sensor architecture. The photo sensor exhibits a high optical responsivity and good signal to noise ratio under the blue light illumination. Afterwards, the detail studies and important issues about the sensing and material characteristics of a-IWO thin film in the TFT sensor are discussed.

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We design a metamaterial for reflective terahertz time-domain spectroscopy. The ability of metamaterials in modulating terahertz waves has attracted people's attention, but conventional micro-nano fabrication encounters the limitation of unit cell size, requiring complex steps and expensive equipment. To overcome these obstacles, we propose a 3D-printed terahertz metamaterial sensor for multi-frequency sensing using a simple double-slit configuration. Using the finite element method, the absorption spectra, electromagnetic field distribution, and blood component sensing capabilities of the metamaterials were evaluated. Our work highlights the potential of the designed metamaterial fabrication process.

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Recently, research on dual-mode biosensors has been gaining increasing interest to
improve the performance of biosensors. In this paper, a computational study is carried out on
SPR chips modified with AuNPs. AuNPs of different sizes were investigated for their SPR
curves and field enhancement factors. The results of this numerical investigation are expected
to be used as a basis for the development of a dual mode biosensor based on SPR/SERS.

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Surface-enhanced Raman scattering (SERS) is a technique that cooperates excitation laser spectroscopy along with the characteristic of nanostructured materials, consequently boosting Raman signals. SERS substrate is developed to detect many kinds of different biomolecules. Al-decorated nitride SERS substrate was fabricated for DNA detection, which was expected for practical application. In that, investigating DNA molecules have been reported in various studies. This SERS substrate can detect a 19-mer DNA with the concentration down to 1E-6 M by using 488nm excitation laser wavelength.

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This study utilizes silicon photonics SOI as the structure to design a wavelength demultiplexer, serving as a simplified spectrometer. The demultiplexing principle involves the use of directional couplers, with adjustable parameters to design four-wavelength wavelength demultiplexers. The dimensions of the device are 250.5 μm in length and 3.6 μm in width, achieving an extinction ratio of 26.9 dB.

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Optical identification (OID) is a technology that can hide digital data and capture
hidden digital data in general printed materials, which can be hidden in general printed
materials through standard printing procedures and standard inks, and coexist with the original
patterns on the printed materials. Through the optical and image processing technology of the
OID Pen, the data hidden in the print can be retrieved. We propose a new idea for the structure
of the OID Pen tip.

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We propose a Mach-Zehnder interferometer fiber sensor formed by filling liquid crystals into a hollow-core fiber (HCF). With the help of MMF, the interference of the cord mode and cladding mode of the HCF can be successfully induced to form a MZI. The measured results show that the temperature sensitivity can be as high as to 825.79 pm/℃ with the strain sensitivity is 2.87 pm/με.

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As the chip has a higher performance and efficiency, devices are made more denser,
making the heat dissipation an important engineering problem. In the study, we realize a
flexible and high-performance photodetector with an effective thermal management through
the use of a graphite substrate. The device can be completely bent with a radius of curvature of
1 cm. After being bent 1000 times, the photodetector still has outstanding photoresponse,
indicating that it has the excellent potential for the applications of flexible systems.

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By employing automated control to perform frequency scanning, time needed for manual measurement of resonance frequency and Q facto of quartz oscillator is reduced. Furthermore, integration of data acquisition and processing systems allows for real-time data acquisition and fitting.

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This research focuses on the growth of Ga2O3 nanostructures by hydrothermal method and investigates their properties as photodetectors. Gallium oxide (Ga2O3) is a promising material for optoelectronic applications due to its wide bandgap and high electron mobility. The study involved the synthesis of Ga2O3 nanostructures using the hydrothermal method, followed by structural characterization using techniques such as XRD and SEM. Photodetectors were fabricated using Ga2O3 nanostructures annealed at various temperatures, and their performance in terms of responsivity, response ratio, and switch-on time was systematically examined. This study provides valuable insights into utilizing Ga2O3 nanostructures for high-performance photodetection devices.

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The spectra image data could be used to estimate the distribution of different types of sediment particles in the sediment core, and based on this, the specific benefits of this integrated system in marine sediment cores. The sample of sediment core, the die seagrass was deposition within. The hyperspectral image and reflectance image of sediment core were presented for discussion.

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A Cd3As2/CdZnTe/Si heterostructure was grown by MBE to be used as a photodetector, with photocurrent being detected from 375 nm to 4.6 µm wavelength. Under an exposed light of 1064 nm wavelength, the photoresponsivity was measured to be 0.52 A/W, with an on/off current ratio of 1.3 × 106 and detectivity of 5.5 × 1011 Jones. While the on/off photoresponse time under 405 nm wavelength was 3.4/67.3 µs.

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