An analog liquid crystal lens-based axial scanning confocal microscope is demonstrated as a 48 &mgr;m continuous
range optical height measurement sensor used to characterize a 2.3 &mgr;m height Indium Phosphide twin square optical waveguide chip.
Fiber-Optic Variable Optical Attenuators (VOAs) are demonstrated using Liquid Crystals (LC) for broadband as well as wavelength tunable applications. Attenuation is achieved by using a beam spoiling approach implemented via electrically reconfigurable non-pixelated no moving parts Nematic LC deflectors. The VOAs feature in-line architecture and polarization insensitive design without the use of bulky polarization splitting and combining optics. The proof-of-concept VOAs in the 1550 nm band demonstrate >30 dB attenuation ranges, low polarization dependent losses and low power consumption. Applications for these VOAs include agile wavelength tunable secure data communications networks and RF sensor systems.
Design and demonstration of a versatile liquid crystal-based scanner is shown for steering a laser beam in three dimensions. The scanner consists of a unique combination of digital and analog control polarization-based beamforming optics resulting in both continuous and random fashion beam steering. The scanner features a novel device biasing method, large aperture beamforming optics, low electrical power consumption, and ultra-fine as well as wide angle coarse beam steering. Demonstrations include one, two and three dimensional beam steering with a maximum of 40.92° continuous scan, all at 1550 nm. The minimum scanner aperture is 1 cm diameter and uses a combination of ferroelectric and nematic liquid crystals in addition to Rutile crystal birefringent prisms.
A versatile high speed 3-D scanner design is proposed and demonstrated for optical beamforming applications such as free-space laser communications, 3-D displays, scanning 3-D optical microscopy, data retrieval, and vision applications. The scanner consists of fast digital-analog control polarization-based optical beamforming cells resulting in complete three-dimensional beamforming programmability. Features include low electrical power consumption and large aperture beamforming optics, digital repeatability, and time multiplexed accurate analog beamforming. Analog frequency and amplitude control of the nematic liquid crystal beamformer cells allows continuous fine scan programmability over a 0.66 mrad horizontal-deflection, 0.75 mrad vertical deflection, and an infinity to 1.84 m focal length longitudinal scan, all at 1310nm. For the first time is demonstrated a coarse angular deflection of an 8-point linear 1-D scan at 1550 nm with a 35 microsecond random-access time.