Abstract: The present, invention relates to liquid crystal compositions having a smectic A structure for use in an optical device in which the composition is sandwiched between a pair of electrodes (12-15). In essence the composition includes a siloxane oligomer (component (a)) which may be seen to construct a layered SmA system of particular spacing and “strength”. Within this structure a low molar mass nematic mesogen (component (c)) is provided that may be considered to be that of a “plasticiser” which moderates the layer “strength”, while simultaneously providing tuneability to the properties of the composition, e.g. its refractive index or dielectric anisotropy. The addition of a side chain liquid crystal polysiloxane (component (d)) allows such systems to be further moderated since they can be considered as binding together the la>¾rs, both within a given layer and between layers.

Abstract: A liquid crystal formulation is described. The liquid crystal formulation comprises a first oligosiloxane-modified nano-phase segregating liquid crystalline material; and at least one additional material selected from a second oligosiloxane-modified nano-phase segregating liquid crystalline material, non-liquid crystalline oligosiloxane-modified materials, organic liquid crystalline materials, or non-liquid crystalline materials, wherein the liquid crystal formulation has an I?SmA*?SmC* phase transition, with a SmC* temperature range from about 15° C. to about 35° C., a tilt angle of about 22.5°±6° or about 45°±6°, a spontaneous polarization of less than about 50 nC/cm2., and a rotational viscosity of less than about 600 cP. Devices containing liquid crystal formulations are also described.

Abstract: The present, invention relates to liquid crystal compositions having a smectic A structure for use in an optical device in which the composition is sandwiched between a pair of electrodes (12-15). In essence the composition includes a siloxane oligomer (component (a)) which may be seen to construct a layered SmA system of particular spacing and “strength”. Within this structure a low molar mass nematic mesogen (component (c)) is provided that may be considered to be that of a “plasticiser” which moderates the layer “strength”, while simultaneously providing tuneability to the properties of the composition, e.g. its refractive index or dielectric anisotropy. The addition of a side chain liquid crystal polysiloxane (component (d)) allows such systems to be further moderated since they can be considered as binding together the la>¾rs, both within a given layer and between layers.

Abstract: A liquid crystal formulation is described. The liquid crystal formulation comprises a first oligosiloxane-modified nano-phase segregating liquid crystalline material; and at least one additional material selected from a second oligosiloxane-modified nano-phase segregating liquid crystalline material, non-liquid crystalline oligosiloxane-modified materials, organic liquid crystalline materials, or organic non-liquid crystalline materials, wherein the liquid crystal formulation is nano-phase segregated in the SmC* phase, has an I?SmC* phase transition, with a SmC* temperature range from about 15° C. to about 35° C., has a tilt angle of about 22.5°±6° or about 45°±6°, and has a spontaneous polarization of less than about 50 nC/cm2, and a rotational viscosity of less than about 600 cP. Devices containing liquid crystal formulations are also described.

Abstract: A liquid crystal electro-optic device. The liquid crystal electro-optic device comprises at least one liquid crystal cell comprising: a pair of substrates having a gap therebetween; a pair of electrodes, the pair of electrodes positioned on one of the substrates or one electrode positioned on each substrate; and a ferroelectric, oligosiloxane liquid crystal material disposed in the gap between the pair of substrates, the ferroelectric, oligosiloxane liquid crystal material exhibiting an I-? SmC* phase sequence wherein the liquid crystal electro-optic device is bistable in operation. The invention also involves a method for making a liquid crystal electro-optic device.

Abstract: A liquid crystal formulation is described. The liquid crystal formulation comprises a first oligosiloxane-modified nano-phase segregating liquid crystalline material; and at least one additional material selected from a second oligosiloxane-modified nano-phase segregating liquid crystalline material, non-liquid crystalline oligosiloxane-modified materials, organic liquid crystalline materials, or organic non-liquid crystalline materials, wherein the liquid crystal formulation is nano-phase segregated in the SmC* phase, has an I?SmC* phase transition, with a SmC* temperature range from about 15° C. to about 35° C., has a tilt angle of about 22.5°±6° or about 45°±6°, and has a spontaneous polarization of less than about 50 nC/cm2, and a rotational viscosity of less than about 600 cP. Devices containing liquid crystal formulations are also described.

Abstract: A liquid crystal formulation is described. The liquid crystal formulation comprises a first oligosiloxane-modified nano-phase segregating liquid crystalline material; and at least one additional material selected from a second oligosiloxane-modified nano-phase segregating liquid crystalline material, non-liquid crystalline oligosiloxane-modified materials, organic liquid crystalline materials, or non-liquid crystalline materials, wherein the liquid crystal formulation has an I?SmA*?SmC* phase transition, with a SmC* temperature range from about 15° C. to about 35° C., a tilt angle of about 22.5°±6° or about 45°±6°, a spontaneous polarization of less than about 50 nC/cm2., and a rotational viscosity of less than about 600 cP. Devices containing liquid crystal formulations are also described.

Abstract: A liquid crystal electro-optic device. The liquid crystal electro-optic device comprises at least one liquid crystal cell comprising: a pair of substrates having a gap therebetween; a pair of electrodes, the pair of electrodes positioned on one of the substrates or one electrode positioned on each substrate; and a ferroelectric, oligosiloxane liquid crystal material disposed in the gap between the pair of substrates, the ferroelectric, oligosiloxane liquid crystal material exhibiting an I-? SmC* phase sequence wherein the liquid crystal electro-optic device is bistable in operation. The invention also involves a method for making a liquid crystal electro-optic device.

Abstract: The present invention provides a method and apparatus for filtering an optical signal. The method includes receiving at least one input optical signal, forming first and second optical signals using the at least one input optical signal, and modifying at least one portion of the first optical signal using a plurality of non-waveguiding electro-optic phase adjusters. The method also includes forming an output optical signal by combining the first optical signal, including the at least one modified portion of the first optical signal, with the second optical signal.

Abstract: The present invention provides an electro-optic gap-cell for waveguide deployment, including a first optical transmission medium formed in at least a portion of a device layer, a second optical transmission medium formed in at least a portion of the device layer, and a slot formed in at least a portion of the device layer, wherein the slot has at least one curved edge, and wherein the slot is disposed adjacent to the first and second transmission media.

Abstract: The present invention provides a method and apparatus for transforming optical wave modes. The apparatus includes a substrate and a first layer of waveguiding material above the substrate, the first layer having a first index of refraction, a first horizontal dimension, and a first vertical dimension. The apparatus also includes a second layer of waveguiding material adjacent the first layer, the second layer having a second index of refraction, a second horizontal dimension, and a second vertical dimension.

Abstract: An optical waveguide phase adjuster with enhanced sensitivity for instance for use in a Mach Zehnder has a monolithic integrated optics waveguide across which one or more thin, e.g. 10 &mgr;m, slots are made. The slots are filled with material whose refractive index varies strongly with temperature or applied field. The insertion loss of such a slot is small for thicknesses of less than about 25 &mgr;m, but begins to rise ever more rapidly thereafter.

Abstract: An optical waveguide Bragg grating spectrally selective reflector is made by ion beam implantation through a photolithographic mask to raise locally the effective refractive index of the guide. This contrasts with the standard method, which uses UV light to raise the index through the agency of the photo-refractive effect.

Abstract: A known form of electrically controlled optical attenuator is formed by a mach Zehnder waveguide configuration with a variable refractive index element in one arm to modify the undulatory spectral characteristic of the network to give a specific attenuation at a specific wavelength. The spectral characteristic of the network makes the attenuation that it provides wavelength dependent. An attenuator with a wavelength dependence of reduced magnitude is provided by the series combination of two Mach Zehnder networks, one having an electrically controllable optical path length adjuster in its longer interference arm, and the other with its adjuster in its shorter arm.

Abstract: An injection laser assembly mounted upon a crystal substrate [10] employing a back facet monitor is disclosed. A graded index lens [34] focuses light from the, typically, high in diversion and low intensity rays output from the back facet of the laser [30]. To allow repeatable and efficient coupling the graded index lens [34] is mounted within a groove defined in the crystal. Several configurations for mounting a photodiode sensor [P1,P2] are possible.