Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature turning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A reflective spatial light modulator (SLM) includes a first substrate, a second substrate and an electro-optic material positioned between the first and second substrates. The first substrate includes a reflective ground layer that acts as a continuous first electrode and the second substrate includes a pixel layer having a plurality of pixel elements formed in a pattern. The pixel elements are formed of a transparent conductive material and are separated by inter-pixel regions formed of a non-conductive material. A transmissivity of the electro-optic material in a vicinity of each of the plurality of pixel elements is controlled by a potential difference applied between the first electrode and a respective one of the pixel elements.

Abstract: A non-blocking N×N cross-connect is provided that has an array of liquid crystal (LC) switches in a grid of planar optical waveguides within a light optical circuit (LOC). LC filled trenches are used in a planar optical waveguide and each trench provides the functionality of a waveguide polarization splitter, a transverse electric (TE) switch cross point, a transverse magnetic (TM) switch cross point, or a waveguide polarization combiner. By combining these elements, a cross-connect system is fabricated.

Abstract: A reflective spatial light modulator (SLM) includes a first substrate, a second substrate and an electro-optic material positioned between the first and second substrates. The first substrate includes a reflective ground layer that acts as a continuous first electrode and the second substrate includes a pixel layer having a plurality of pixel elements formed in a pattern. The pixel elements are formed of a transparent conductive material and are separated by inter-pixel regions formed of a non-conductive material. A transmissivity of the electro-optic material in a vicinity of each of the plurality of pixel elements is controlled by a potential difference applied between the first electrode and a respective one of the pixel elements.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel crosstalk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A non-blocking N×N cross-connect is provided that has an array of liquid crystal (LC) switches in a grid of planar optical waveguides within a light optical circuit (LOC). LC-filled trenches are used in a planar optical waveguide and each trench provides the functionality of a waveguide polarization splitter, a transverse electric (TE) switch cross-point, a transverse magnetic (TM) switch cross-point, or a waveguide polarization combiner. The planar optical waveguide has a refractive index substantially equal to the lowest index of refraction of the LC material. By combining these elements, a cross-connect system is fabricated. Also disclosed is a dynamically adjustable prism constructed with a liquid crystal material.

Abstract: A non-blocking N×N cross-connect is provided that has an array of liquid crystal (LC) switches in a grid of planar optical waveguides within a light optical circuit (LOC). LC filled trenches are used in a planar optical waveguide and each trench provides the functionality of a waveguide polarization splitter, a transverse electric (TE) switch cross point, a transverse magnetic (TM) switch cross point, or a waveguide polarization combiner. By combining these elements, a cross-connect system is fabricated.

Abstract: An optical system of the present invention includes a reflective liquid crystal device having a plurality of independently activated liquid crystal elements, and an optical element for directing a plurality of input light beams at the reflective liquid crystal device such that each input light beam impinges upon one of the liquid crystal elements. Each liquid crystal element of the reflective liquid crystal device includes a transparent first electrode, a reflective second electrode spaced apart from the first electrode, and a liquid crystal medium disposed between the first and second electrodes. The liquid crystal elements are independently operable to change between half-wave and zero retardation states in response to an applied voltage.

Abstract: An optical system according to the present invention includes a beam polarization combiner for receiving first and second sets of input beams, and a reflective spatial light modulator having a plurality of individually activated modulating elements each corresponding to a respective one of the different wavelengths of the input beams. Each input beam is directed at a modulating element of corresponding wavelength with input beams of the first and second sets impinging upon the modulating element from respective first and second incoming paths. Each modulating element selectively changes the input beams such that the outgoing path for each reflected beam of each set is superimposed on the incoming path for the other set. The beam combiner receives the reflected sets of beams and directs them in different directions based upon their polarization. The optical system may be used in a wavelength selective switch or a dynamic spectral equalizer.

Abstract: A wavelength selective cross-connect switch for selectively switching wavelength-separated input channels between two optical input signals. The cross-connect switch includes two dispersive elements, where each dispersive element receives an optical input signal and disperses it into a plurality of wavelength-separated input channels. The cross-connect switch also includes a switching array mechanism, such as a micro-electro mechanical system (MEMS) shutter array, receiving the plurality of wavelength-separated input channels from each of the dispersive elements and operative for selectively switching one or more of the wavelength-separated input channels between the optical signals.

Abstract: A symmetric optical switch for selectively switching wavelength channels between four optical inputs. The symmetric optical switch includes two dispersive elements receiving optical inputs from respective optical fibers where the optical inputs are dispersed into a plurality of wavelength-separated input channels. The symmetric optical switch also includes a plurality of circulators disposed on each optical fiber and a switching array mechanism that receives the plurality of wavelength-separated input channels from each of the dispersive elements. The shutter array simultaneously switches one or more pairs of the wavelength-separated input channels between four optical inputs. Each circulator that is disposed on the associated optical fiber operates with the shutter array to form an eight port device so as to independently switch wavelength channels.

Abstract: The present invention discloses an optical cross-connection device. The device is fabricated by disposing liquid crystal polarization modulators on a polarization beam splitting cube. The modulators effect switching by changing the polarization state of the light signal passing through the liquid crystal cell. The beam splitting cube directs the signal according to the polarization state. Several prisms are also disposed on the cube. The prisms are used to direct the light signals inside the switch. The device is simple to make, relatively inexpensive, and compact. Because it uses standard LCD technology there are very few mechanical parts subject to fatigue and other reliability issues.

Abstract: A tunable liquid crystal switch is disclosed. An electronic controller provides an electronic drive scheme for achieving low intra-channel cross-talk of less than −40 dB using only electronic compensation. A cross-talk less than −50 dB is provided by combining coarse temperature tuning and electronic compensation. This is acheived by designing the thickness of the liquid crystal device to cause a minimum to occur at a wavelength longer than a longest operating wavelength and at a temperature greater than a maximum operating temperature. This ensures that the liquid crystal device is tunable over all operating wavelengths and temperatures using electronic compensation.

Abstract: A variable delay device of the type used to correct for polarization mode dispersion in a signal transmitted over an optical communications system. In an exemplary embodiment, the variable delay device uses a plurality of polarization rotators and delay elements aligned in series and alternating with one another. The polarization rotators map the fast polarization mode component of the incoming optical signal to the slow axes of one or more delay elements, to achieve a desired pattern of relative incremental delays which total the initial differential delay being compensated. The delay elements may have uniform or non-uniform incremental delay values, and the polarization rotators may be selectively actuated to achieve the desired pattern of delay values corresponding to the intended total delay.

Abstract: An electro-optic polarizor, grating assembly or cell (10) includes a first glass plate (12) to form the foundation of the cell. A first alignment surfactant (14) is coated on one surface of the first glass plate (12). Similarly, a second alignment surfactant (24) is coated on one surface of a second glass plate (22). A transparent interdigitated electrode pattern (30) is disposed between the second glass plate (22) and the second alignment surfactant (24). A thin film of homeotropically aligned nematic liquid crystal (40) is sandwiched between the first and second alignment surfactants (14) and (24) for applying a lateral electric field caused by the control voltage or signal (50) across the liquid crystal (40) to alter the optical properties of the liquid crystal (40) such that a polarization depended grating (60) is induced by the lateral electric field (50).

Abstract: A flat screen autostereoscopic display for bright wide angle stereoscopic images employs a flat screen on which are displayed a light pattern such as a plurality of regularly spaced, thin, vertical light emitting lines. The light lines are formed through use of electrically switchable materials such as liquid crystal or electrochromic materials. A transmissive electronic display, e.g., a liquid crystal display, is located in front of the light lines. The display and light lines are arranged in such a way that an observer sees the light emitting lines through one set of pixels with the left eye and the same lines through a different set of pixels through the right eye. Methods and apparatus for the simultaneous formation of a two-dimensional image and a three-dimensional image on such a transmissive electronic display, and for moving or dragging the display area of the three-dimensional image from one location to another on said display, are also disclosed.