Coadna Photonics Inc.

Ii-vi Delaware, Inc.

Kent State University

Rockwell Collins, Inc.

Jack Robert Kelly

Haiji J Yuan

Helen Chen

Guomin Jiang

Hudson Washburn

Qingyu (Tom) Li

Qingyu Li

Tatiana A Sergan

Yimin Ji

Xuewu Liu

Marina Lavrentovich

Tadayuki Kameyama

Oleg Yaroshchuk

Liang-Chy Chien

Yuuichi Nishikouji

Alan A Fennema

Shu Li

Meng Xue

Yuriy Reznikov

Tom Li

Thomas J Schwartz

Jim Yuan

Kun Gao

Lawrence Wang

Wilfredo C Nanita

Oswald Correya

Fenghua Li

Oliver Lu

Mingji Cui

Xinran Wang

Gordon Jiang

David Heineman

Simon He

Lixin (Lawrence) Wang

Haijun Yuan

Advanced hologram techniques pre-calculate holograms to be displayed on an LCoS switch panel of a wavelength selective switch (WSS) module. The holograms are generated offline and are then stored on the WSS module for later retrieval. Each of the holograms is associated with a defined parameter, such as an attenuation level, and each of the holograms is configured to create a reconfigurable phase grating profile or pattern of the pixels of the LCoS switch panel. Each phase pattern selectively directs desired diffraction orders of optical channels from the LCoS switch panel for output to selected ports and selectively directs undesired diffraction orders away from the ports and at a desired attenuation level. During operation, the WSS module can retrieve the stored holograms. Interpolation can determine intermediate holograms between parameter values, and a ramp function can be added to the pattern to account for steering adjustments.

Method for pre-calculating and applying optimized phase patterns to LCoS switch panel of WSS module

A voltage-controlled optical wedge is formed by creating an adjustable voltage gradient along the length of a relatively large-sized LC cell. A pair of bias voltages (AC voltages) are applied at the opposing side terminations of the LC cell, their RMS values selected to create a continuous phase variation along the length of the cell, where a defined phase variation is associated with a specific beam steering angle. Adjustments in the applied bias voltages (specifically, changes in the RMS values of the bias voltages) result in changing the beam steering angle, providing for active, controllable beam steering as a function of time. The LC cell may be configured to provide either a linear or nonlinear continuous phase variation, as preferred for different beam steering applications.

Tunable optical wedge for beam steering

A two-step optimization process is utilized to define an optimal phase profile for a LCoS spatial light modulator. The two-step optimization process first utilizes a nonlinear constrained optimization (NCO) program to determine the specific parameters required to obtain an optimal phase profile (hologram), where the 'optimal phase profile' is typically defined as that profile which achieves maximum diffraction efficiency for optical switching. Following this first step, phase scaling (and perhaps an adjustment in the number of pixels per period) is employed to slightly modify the values of the optimal phase profile to effectively suppress crosstalk peaks. If any orders still exhibit an unacceptable level of crosstalk, these orders are then subtracted from the phase profile to create the final design.

Optimization of wavelength selective switch using phase control of liquid crystal spatial light modulator

A multiple wavelength selective switch has an optics assembly to receive a first input optical signal from a first ingress port and a second input optical signal from a second ingress port. A switch assembly has a single switching mechanism to direct the first input optical signal to the optics assembly as a first output optical signal and the second input optical signal to the optics assembly as a second output optical signal. The switch assembly directs the first output optical signal to a first egress port selected from the first set of egress ports and directs the second output optical signal to a second egress port selected from the second set egress ports. The first egress port and the second egress port have the same wavelength channel. The multiple wavelength selective switch supports an arbitrary number of wavelength channels that can be switched at the same time. Each switch assembly directs signals from a set of ingress ports to a set of egress ports sharing the same wavelength channel.

Multiple wavelength selective switch with shared switch

An optical switch includes an optical waveguide to route an input optical beam. At least one polarization switch receives the input optical beam from the optical waveguide. At least one birefringent wedge is associated with the at least one polarization switch. The at least one polarization switch and at least one birefringent wedge operate to direct the input optical beam to two or more output locations through control of the polarization switch.

Apparatus and method for optical switching with liquid crystals and birefringent wedges

An optical switching apparatus includes at least one optical waveguide to deliver at least one input optical beam. A dispersion device spatially separates the at least one input optical beam into individual wavelength channels. An optical power device aligns the individual wavelength channels. An optical switch has at least one transflective polarizing element, at least one birefringent wedge and at least two polarization switches. The individual wavelength channels are directed to independently addressable regions of the polarization switches for wavelength selective switching. A second optical power device aligns the individual wavelength channels from the optical switch. A second dispersion device spatially combines individual wavelength channels from the second optical power device. At least one output optical waveguide receives at least one of the individual wavelength channels from the second dispersion device.

A method for resetting a polarization controller includes determining that the phase magnitude is associated with a first range of phase angles and generating a first control signal having a first characteristic if the phase magnitude is increasing, and generating the first control signal having a second characteristic if the phase magnitude is decreasing. The phase magnitude associated with a second range of phase angles is determined. The first control signal having the second characteristic is generated if the phase magnitude is increasing. The first control signal having the first characteristic is generated if the phase magnitude is decreasing.

Apparatus and method for controlling polarization in an optical communications medium

An exemplary polarization controller includes a first optical element having a first optical axis and configured to receive light having a first phase, a second optical element having a second optical axis and configured to emit the light having a second phase, and a third element having a third optical axis. At least a portion of the third element is interstitial to the first element and the second element. The exemplary controller also includes at least two drivers, both of which can operate in accordance with an exemplary method of present invention.

A display system is disclosed. The display system includes a light source and a display element illuminated by the light source. The display system also includes a first liquid crystal polymer compensation film layer that is disposed adjacent to the first side of the display element. The display also includes a second liquid crystal polymer compensation film layer disposed adjacent a second side of the display element. Further, the display system includes a third liquid crystal polymer compensation film layer that is disposed adjacent the second liquid crystal polymer compensation film layer.

Viewing angle for liquid crystal display system and method

An elliptically polarizing plate, comprising a polarizer, a first optical anisotropic layer having positive refractive index anisotropy and an optical axis of the anisotropy that is tilted, and a second optical anisotropic layer having negative refractive index anisotropy and an optical axis that is tilted, have accurate retardation compensation of a liquid crystal cell, and the liquid crystal display maintains a display contrast having a sufficient visibility when the viewing angle is changed and which does not generate colorization.

Elliptically polarizing plate and liquid crystal display

An optical compensation film for a liquid crystal display is provided wherein the film is a polymer that is capable of producing light induced anisotropy. The film is irradiated with light to form an optical axis or axes.

Optical compensation film for liquid crystal display

An achromatic half wave plate includes a first twisted nematic liquid crystal layer, a second twisted nematic liquid crystal layer, and a uniaxial half wave plate between the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer. In one embodiment the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer have an identical twist angle of 135 degrees. The optic axis at the entrance of the first twisted nematic liquid crystal layer is substantially orthogonal to the optic axis at the exit of the second twisted nematic liquid crystal layer.

Apparatus and method for achromatic liquid crystal electro-optic modulation

The invention includes an apparatus for processing an input optical beam. The apparatus has at least one variable optical element to dynamically alter the polarization state of an optical beam to form a polarization-altered optical beam, wherein the polarization-altered optical beam includes elliptical polarization. At least one wave plate operates on the polarization-altered optical beam, each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer, operating in conjunction with the at least one variable optical element and wave plate, alters the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produces an output optical beam with transmitted amplitude adjusted as a function of wavelength.

Apparatus and method for controlling optical gain profiles

An apparatus for processing an optical beam has at least one variable optical element to dynamically alter the polarization state of a polarized optical beam to form a polarization-altered optical beam. The polarization-altered optical beam includes elliptical polarization. The at least one variable optical element is a compound birefringent crystal with a designed retardation response to temperature variations. In one embodiment, the compound birefringent crystal has a designed retardation response that is substantially invariant with operating temperature variations. At least one wave plate processes the polarized optical beam. Each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer is operative in conjunction with the at least one variable optical element and wave plate to alter the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produce an output optical beam with transmitted amplitude adjusted as a function of wavelength.

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Stow, OH, United States of America

Jack Robert Kelly