Session Index

S5. Optical Design, Testing, and Engineering

Optical Design, Testing, and Engineering II
Friday, Dec. 1, 2023  15:15-17:30
Presider: Prof. Hsuen-Li Chen (National Taiwan University, Taiwan) Prof. Cheng-Huan Chen (National Yang Ming Chiao Tung University, Taiwan)
Room: 92225 (2F)
15:15 - 15:45
Manuscript ID.  0650
Paper No.  2023-FRI-S0502-I001
Invited Speaker:
Morgan Lu
Pancake lens design and simulation for VR glasses
Morgan Lu, Synopsys (Taiwan)

With the development of the metaverse, virtual reality (VR) is becoming more and more popular, so the
design process for these systems is rapidly evolving. Designing a VR system that features pancake lenses
can produce a system with impressive optical performance as well as a competitive advantage in size,
weight, and cost.
The main design concept of a pancake lens is a folded ray path where polarized rays reflect between
polarization elements. This can be beneficial for increasing the total optical path length within a shorter
overall length. In other words, it allows you to decrease the thickness between the display and human
eye, which can significantly reduce the volume required for the helmet unit.
A pancake lens system includes three primary parts: a lens module, polarization elements, and human
visual components. For the lens module, imaging performance is the most important aspect that needs to
be considered and optimized. Precisely simulating image quality and efficiently optimizing with design
requirements are key for lens design. For the polarization elements, you must consider the “polarization
axis” in the computation. Polarization properties are usually applied to a curved lens surface in pancake
lens system, because the polarization axis varies along a curved surface. If you used a flat polarizer, the
polarization axis would be the same for each point on the lens surface, and the result would be very
different from the curved lens case. Lastly, we must combine all components and check the visualization
effect to discover if any anomalies exist. For example, a non-ideal polarization state may cause issues
such as leaked rays, flare, or ghost images. These must be identified and reoptimized at a system level.
This talk will introduce an integrated solution to a pancake lens design using Synopsys CODE V, RSoft
DiffractMOD RCWA, and LightTools software. CODE V is an imaging design tool for modeling manytypes of imaging optical systems. We will use it to build a triplet lens and optimize the lens to meet the
specifications. RSoft DiffractMOD is an efficient tool for computing periodical structures. In this case
study, we will use a wire grid polarizer and retarder modeled in RSoft DiffractMOD to selectively
transmit and reflect light. Once we complete the lens design and polarization elements design, the results
will be imported into LightTools, where we will model the displays and eye receiver model and perform
system simulation. We can also use LightTools features to filter the primary path and unwanted path for
stray light analysis. With this seamless cross-product workflow, we can easily achieve the desired
performance and reduce stray light impact for this VR system.

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15:45 - 16:00 Award Candidate (Paper Competition)
Manuscript ID.  0070
Paper No.  2023-FRI-S0502-O001
Wei-Cheng Hung An Immersive Head-Mounted Display using a Low Aberration Liquid Crystal Lens
Wei-Cheng Hung, Tzu-Yu Tai, Jui-Wen Pan, Shie-Chang Jeng, National Yang Ming Chiao Tung University (Taiwan)

We demonstrate an immersive head-mounted display (HMD) system in which a hole-patterned electrode (HPE) liquid crystal (LC) lens with a low aberration is incorporated, which is suitable for both hyperopic and myopic users.

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16:00 - 16:15 Award Candidate (Paper Competition)
Manuscript ID.  0271
Paper No.  2023-FRI-S0502-O002
Kai-Hsiang Wang Model-based Adaptive Optics for Multiphoton Microscopy
Kai-Hsiang Wang, Jui-Tse Yang, Cheng-Jung Yang, Chia-Yuan Chang, National Cheng Kung University (Taiwan)

Multiphoton excited fluorescence microscopy (MPEFM) systems have emerged as
powerful imaging tools in life science and biomedical research due to their high-resolution
imaging capabilities, deep tissue penetration, and three-dimensional reconstruction capabilities. In this study, we present the integration of adaptive optics (AO) into an MPEFM system to enhance the image quality through aberration correctio. By harnessing the high responsivity of a deformable mirror (DM) and employing Zernike polynomials to represent
various aberrations, we achieved imaging quality improvement. Before aberration correction, a three-step identification process was implemented to accurately compensate each aberration.

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16:15 - 16:30 Award Candidate (Paper Competition)
Manuscript ID.  0885
Paper No.  2023-FRI-S0502-O003
Cheng-Yang Lee Research on White and Infrared LED Arrays Applied in Automotive Headlamp
Cheng-Yang Lee, Mei-Lin Chen, Chi-Shou Wu, Tsung-Hsun Yang, Yeh-Wei Yu, Ching-Cherng Sun, National Central University (Taiwan)

We propose a novel optical design concept for automotive headlamp. The low beam of this optical system utilizes visible light to illuminate the road, while the high beam employs 850nm infrared light to detect sensors on oncoming vehicles. The low beam mode is designed in accordance with the ECE R112 vehicle safety regulations.

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16:30 - 16:45 Award Candidate (Paper Competition)
Manuscript ID.  0376
Paper No.  2023-FRI-S0502-O004
Siang-Yu Yeh Neural Network Assisted Deformable Mirror Identification at Oblique Incidence
Siang-Yu Yeh, Cheng-Yu Wu, Xin-Li Lee, Chia-Yuan Chang, National Cheng Kung University (Taiwan)

Due to the incident angle change and the coupling effect of DM channels, to identify the DM voltage vectors for generating individual Zernike mode is complicated and not intuitive. The present study proposes the deep learning neural network to assist the DM identification and find the control vectors. We have successfully trained the SHWS analysis model. A DM with tip-tilt compensation is placed at angle of 45 degree with the optical axis so that the reflected laser power efficiency can be maximized due to no beam splitter is required.

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16:45 - 17:00 Award Candidate (Paper Competition)
Manuscript ID.  0790
Paper No.  2023-FRI-S0502-O005
Daryl Lim Optical Simulations for Laser-Induced Breakdown Spectroscopy for Optimization of Signal Collection Optics
Daryl Lim, C.S. Suchand Sandeep, Murukeshan Vadakke Matham, Nanyang Technological University (Singapore)

Laser-induced breakdown spectroscopy (LIBS) is a versatile tool used for elemental analysis. However, there are certain issues associated with repeatability and sensitivity when dealing with low sample concentrations in liquid LIBS. In addition, the measurements can be time-consuming. Therefore, it is very important to optimize the signal collection optics of the LIBS system to improve signal collection efficiency. In this work, we report a method to optimize LIBS signal collection optical system using optical simulations with a commercial ray tracing package, TracePro®. LIBS signal recorded using the optimized system is also presented.

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17:00 - 17:15 Award Candidate (Paper Competition)
Manuscript ID.  0939
Paper No.  2023-FRI-S0502-O006
Hao-Wen Chia Development of a Wafer Warpage Measurement Technique Based on Shadow Moiré
Hao-Wen Chia, Hung-Lin Hsieh, Yu-Cheng Yang, National Taiwan University of Science and Technology (Taiwan)

Warpage measurement of unpolished wafers is a research topic to be overcome. Due to the fact that the surfaces of such wafers can cause the measurement beam to travel along unexpected paths, most optical inspection techniques cannot accurately provide information about the warpage of unpolished wafers. To overcome this problem, we propose a wafer warpage measurement technique based on the shadow moiré effect. Experimental results prove that this technique can accurately measure wafer warpage, with a measurement resolution superior to sub-micron levels.

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17:15 - 17:30 Award Candidate (Paper Competition)
Manuscript ID.  1013
Paper No.  2023-FRI-S0502-O007
Thi-Thu-Ngoc Le Maintaining the Murcott Quality using UVC LED Array
Thi-Thu-Ngoc Le, National Central University (Taiwan); Chung-Ta Liao, Taichung District Agricultural Research and Extension Station (Taiwan); Chi-Shou Wu, Shih-Kang Lin, Tsung-Hsun Yang, Yeh-Wei Yu, Ching-Cherng Sun, National Central University (Taiwan)

We designed and fabricated a UVC LED array that has the potential to limit the fungal infection for murcotts. The UVC LED array was designed suitable for 16 occupied positions of Murcotts. The irradiance was carefully measured on the target section. In terms of vivo conditions, the observation after several weeks of treatment disclosed that the disease symptoms on the irradiated murcotts saw a significant reduction compared to their peer without treatment, where the severity of green mold was effectively inactivated than the stem end rot on murcotts.

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