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Physical Limitations And Fundamental Factors Affecting Performance Of Liquid Crystal Tunable Lenses With Concentric Electrode Rings, Liewi Li, Doug Bryant, Tony Van Heugten, Philip Bos
Physical Limitations And Fundamental Factors Affecting Performance Of Liquid Crystal Tunable Lenses With Concentric Electrode Rings, Liewi Li, Doug Bryant, Tony Van Heugten, Philip Bos
Philip J. Bos
A comprehensive analysis of fundamental factors and their effects on the performance of liquid crystal (LC)-based lenses is given. The analysis adopts numerical LC director and electric field simulation, as well as scalar diffraction theory for calculating the lens performance considering different variable factors. A high-efficiency LC lens with concentric electrode rings is fabricated for verifying and enriching the analysis. The measurement results are in close agreement with the analysis, and a summary of key factors is given with their quantitative contributions to the efficiency.
Near-Diffraction-Limited Tunable Liquid Crystal Lens With Simplified Design, Liwei Li, Doug Bryant, Tony Van Heugten, Dwight Duston, Philip Bos
Near-Diffraction-Limited Tunable Liquid Crystal Lens With Simplified Design, Liwei Li, Doug Bryant, Tony Van Heugten, Dwight Duston, Philip Bos
Philip J. Bos
A high-efficiency tunable refractive lens based on liquid crystals with concentric electrode rings and a simple unique design of a resistor network is reported, and used to assess the performance of an optimized electrically tunable lens. It has a large number of phase control points to be able to accurately control the phase profile and produce high efficiency. The lens design uses resistors between neighboring electrodes to minimize external connections. The lens optical path difference is measured as a near perfect parabolic shape and the Strehl ratio of about 80% is obtained (comparing to a high-quality glass lens). Image evaluations …
Finite-Difference Time-Domain Calculations Of A Liquid-Crystal-Based Switchable Bragg Grating, Bin Wang, Xinghua Wang, Philip Bos
Finite-Difference Time-Domain Calculations Of A Liquid-Crystal-Based Switchable Bragg Grating, Bin Wang, Xinghua Wang, Philip Bos
Philip J. Bos
A polymer-wall-confined transmissive switchable liquid crystal grating is proposed and investigated by two-dimensional finite-difference time-domain optical calculation and liquid-crystal-director calculation, to our knowledge for the first time. The results show how to obtain optimized conditions for high diffraction efficiency by adjusting the liquid crystal parameters, grating geometric structure, and applied voltages. The light propagation direction and efficiency can be accurately calculated and visualized concurrently.
Multispectrum, Spatially Addressable Polarization Interference Filter, Salman Saeed, Philip Bos
Multispectrum, Spatially Addressable Polarization Interference Filter, Salman Saeed, Philip Bos
Philip J. Bos
We review current synthesis techniques for generating and improving birefringent filters. The relationship between wave-plate orientation and the resulting spectral output is shown to be that of a simple Fourier transform. By using this relationship and starting from the fan Sole configuration, we easily generated plate orientations providing lower sidelobe levels and improved finesse. We outline a method by which filters can be constructed to provide from 0 to 100% of the desired passband in a continuous fashion. Such a filter can be stacked to allow rapid control of any number of passbands and is shown, as an example in …