Liquid-Crystal-Based Visible-Light Integrated Optical Phased Arrays

Integrated optical phased arrays: augmented reality, LiDAR, and beyond

“…In this thesis, novel integrated-optical-phased-array devices, systems, results, and applications will be presented [1][2][3][4][5][6].…”

“…Finally, in Ch. 4, a novel transparent integrated-phased-array-based holographic display will be proposed as a highly-discreet and fully-holographic solution for the next generation of augmented-reality head-mounted displays; novel passive near-eye displays that generate holograms [18,19], the first integrated visible-light liquid-crystalbased phase [20,21] and amplitude [22,23] modulators, and the first actively-tunable visible-light integrated optical phased arrays [24] will be presented.…”

“…First, a variety of novel integrated visible-light components, required for the VIPER display, will be demonstrated. The first integrated visible-light liquid-crystalbased phase [20,21] and amplitude [22,23] modulators (with device lengths an order of magnitude smaller than traditional inefficient thermo-optic visible-light modula-Introduction…”

On-chip 2D beam-steering with a liquid-crystal-tunable optical phased array

“…2D OPAs also generate multiple grating-lobes due to the limited antenna density, resulting in a signi cant reduction of the main-beam power. Although advanced phase shifters such as electro-optic [18], liquid crystal [20], multi-pass thermo-optic [13] and microelectro-mechanical-system (MEMS)-actuated shifters [21] have been demonstrated, large-scale and dense integration in a 2D array still remains elusive. Liquid crystal-on-silicon (LCOS) spatial light modulators [22][23][24] are another approach for 2D beam-steering, but their slow response has severely hindered their applications.…”

Power-Efficient Silicon Nitride Thermo-Optic Phase Shifters for Visible Light

“…Phase shifters based on thermally-tuned SiN microdisks and microrings have P π of 0.68−2.1 mW at wavelengths of 488 and 530 nm [19][20][21]; however, the low power consumption is attained at the expense of increased wavelength and fabrication error sensitivity compared to non-resonant structures. SiN phase shifters with liquid crystal cladding are expected to have significantly lower power consumption and such devices have been demonstrated at a wavelength of λ = 630 nm [22,23], but post-processing steps are required to apply and encapsulate the liquid crystal. Low-loss lithium niobate nanophotonic waveguides have been demonstrated at red and near-infrared wavelengths (634 − 638 nm, 720 − 850 nm), and ultra-low power phase shifters have been demonstrated at a wavelength of 850 nm [24]; however, the incompatibility of lithium niobate processing with standard silicon photonics fabrication limits the levels of integration that may be achieved.…”