Xtellus, Inc.

Spectraswitch, Inc.

Shanti A Cavanaugh

Louis J Molinari

Mark Young

James M Hood

Lindsay W Austin

Edward Palen

Grady K Anderson

Gary M Zalewski

Mark A Crowley

Neil J Spatz

A liquid crystal cell fabrication method is presented that utilizes a deposited metal gasket moisture barrier bonding two opposing plates of glass each having a spacer layer to accurately control cell gap thickness along with an optional integrated thermal sensor and heater deposition layer sandwiched between both opposing plates of glass.

Fabrication method for liquid crystal cell

A liquid crystal cell is presented that utilizes a deposited metal gasket moisture barrier and support membrane bonding two opposing plates of glass, a thin film spacer layer to accurately control cell gap thickness, and an optional integrated thermal sensor and heater deposition layer sandwiched therebetween.

Liquid crystal cell platform

A wavelength locker operates with a reference tunable liquid crystal filter having integrated photodetectors deposited on the front and backside of the liquid crystal cell to track power intensity of the accepted passband signal and its rejected signal compliment at a 50% power point where the two signals cross on the side of the filter transmission peak. The tunable filter is tuned by an offset wavelength from the laser wavelength such that 50% power is transmitted through the filter at the center wavelength of the laser. The wavelength locker may be configured with a liquid crystal tunable etalon or a liquid crystal tunable bandpass filter. A method for locking an optical signal to a desired frequency is also included and provides a substantially linear feedback signal computed by dividing the rejected signal power by the accepted signal power and passing it to laser transmitter to enable it to correct for frequency drift. Optional features of the present invention include an integrated thermal sensor and heater and temperature compensation control schemes.

Wavelength locker with liquid crystal tunable filter generating transmitted and reflected outputs

A multi-pixel optical processing system includes a multi-pixel liquid crystal cell platform having a deposited metal gasket moisture barrier bonding two opposing substrates each having a spacer layer to accurately control cell gap thickness. A library of specialized pixel constructs is included that can be configured to yield predetermined optical functions at referential locations in the platform. A control system is provided utilizing a time division scheme that multiplexes temperature sensing and heating functions across an optional integrated active thermal element that may be integrated inside the liquid crystal platform. A calibration process characterizes the profile of the cell and generates a polynomial regression formula that provides the voltage drive output for all pixels in the platform based on the platform temperature and state of each pixel.

Multi-pixel liquid crystal cell array

A polarization insensitive narrowband tunable filter utilizes an active liquid crystal cell to change the index of refraction and tuning of a waveguide resonant filter employing a nanostructured waveguide grating and polarization beam splitters to independently channel and convert S- and P-polarization states into optically and geometrically parallel beams which pass through the device. A multi-pixel configuration offers extended tuning range by employing a 1&#xd7;N optical switch or splitter and N tunable pixel-filters each having offset center frequency enabling the tuning range of one pixel to partially overlap another pixel rendering the device and 1&#xd7;N switch or splitter capable of scanning pixels to yield an expanded continuous tuning range mode. Optional features of the present invention include deposited photodetectors, deposited metal gasket moisture barrier, deposited spacer layer with high cell gap tolerance, a deposited thermal sensor and heater and related temperature compensation control schemes.

Narrow band tunable filter with integrated detector

A thermal control system for a liquid crystal cell is presented that may utilize a time division scheme to multiplex temperature sensing and heating functions across active thermal elements such that the cell may generally be kept at a constant temperature. A calibration process characterizes the profile of the cell and generates a polynomial regression formula that provides the voltage drive output for a temperature and cell state input. The control system stores the state of the liquid crystal cell, the regression formula, and reads the temperature of the liquid crystal cell to compute end assert the temperature compensated voltage drive.

Thermal control system for liquid crystal cell

A twisted nematic liquid crystal variable optical attenuator is presented with one substrate that includes a integrated subwavelength nanostructured polarizer. The device may incorporate an integrated isolator whereby a substrate of the liquid crystal sandwich is formed from doped garnet to comprise a faraday rotator etched with a subwavelenth optical nanostructured polarizing grating and enabling the substrate to function as an isolator. The liquid crystal variable optical attenuator may include a deposited metal gasket moisture barrier bonding the opposing top and bottom substrates each having a spacer layer to accurately control cell gap thickness. The liquid crystal variable optical attenuator may also include an integrated thermal sensor and heater deposition layer sandwiched between or deposited on at least one or both opposing substrates.

Liquid crystal variable optical attenuator

A liquid crystal optical processor is configured in various applications, including a liquid crystal optical switch, polarization independent variable optical attenuator, wavelength selector switch, optical multiplexer and demultiplexer, tunable filter and flexible optical add drop multiplexer. The optical processor is generally configured to include a deposited metal gasket moisture barrier bonding two opposing substrates each having a spacer layer to accurately control cell gap thickness. The optical processor may be temperature insensative and be configured in one or more pixel configurations. The optical processor may include integrated subwavelength optical gratings. It may also include an integrated thermal sensor and heater deposition layer sandwiched between or deposited on at least one or both opposing substrates.

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Santa Rosa, CA, United States of America

Shanti A Cavanaugh