Abstract: A device and method for the spectrally-designed and controlled attenuation of a light signal, including an attenuation structure which may be placed in the proximity of a waveguide's core and which comprises a base material system containing non-uniformities having optical properties that are different from those of the host. These non-uniformities may have various natures, geometrical forms and sizes and may be created, doped or otherwise introduced in the base material system to obtain externally controllable optical properties of the whole composite material providing a broadband spectral performance.

Abstract: In a method for coupling an optical waveguide to a light emitting diode (LED) within a resin case, an input end of the optical waveguide is mounted proximal to a surface formed in the resin case parallel to a light-emitting face of the LED. The optical waveguide and the resin case can be bonded by a light or thermally curable resin that is applied and subsequently solidified. The light or thermally curable resin may be a photopolymer sensitive to light emerging from the waveguide. An automated coupling system is provided to optimize the coupling conditions using the in-coupled light efficiency feedback and controller. Finally a method is described allowing the coupling efficiency to be controlled using external excitation forces or light intensity variations, using electro-optic, magneto-optic, thermo-optic, light polarization sensitive or nonlinear properties of the filler material used between the resin case and waveguide.

Abstract: A variable optical attenuator comprises a portion of a waveguide through which optical energy can propagate having a side surface through which optical energy can be extracted; a layer of thermo sensitive material having controllable optical properties, covering the side surface of the portion; a helicoidal heating element wrapped around the waveguide and covering at least the layer. The helicoidal heating element can be used to control the optical properties of the material by inducing a thermal transfer profile on the material using the heat dissipation of the heater through the material; wherein a wave propagation in the waveguide is influenced by the optical properties of the material controlled by the heating element.

Abstract: Described is a composite liquid crystalline mixture having a low refractive index and a chemical reactive power that makes it capable of minimizing an anchoring energy when in contact with silica. This mixture comprises: (a) low ordinary refractive index nematic liquid crystal of a single type or a mixture of low ordinary refractive index nematic liquid crystals of different types; (b) at least one reagent compound capable of reducing the anchoring energy via a chemical shielding process and from which originates a decoupling effect with a glass interface leading to the reduction of the anchoring energy and appropriately orienting a liquid crystal director at this interface; and (c) at least one low refractive index additive having a relatively low viscosity. The above mixture is useful in waveguide tuning applications.

Abstract: A device and method for the spectrally-designed and controlled attenuation of a light signal, including an attenuation structure which may be placed in the proximity of a waveguide's core and which comprises a base material system containing non-uniformities having optical properties that are different from those of the host. These non-uniformities may have various natures, geometrical forms and sizes and may be created, doped or otherwise introduced in the base material system to obtain externally controllable optical properties of the whole composite material providing a broadband spectral performance.

Abstract: A variable optical device for selectively controlling propagation of light within an optical waveguide. The optical device comprises: a relief modulation defining a grating disposed proximal the waveguide and having a respective grating index of refraction nG; a matrix surrounding at least the relief modulation, the matrix having an index of refraction nEO that is controllable, in response to a selected stimulus between a first value that is substantially equal to the grating index of refraction nG, and a second value that is different from nG; and at least one electrode for supplying the selected stimulus to the matrix-grating system.

Abstract: A material composition for optically coupling two optical components, a method for making such a coupling and the resulting device are provided. The material composition includes a first material system polymerizable by light, and a second material system having a refractive index smaller than that of the first material system after its polymerization. The second material system is miscible with the first prior to its polymerization, but repulsed by it afterwards. The material composition is injected between two optical components, such as a light source and waveguide or two waveguides, and exposed to light beams from both sides to generate a light guiding channel therebetween. The transverse refractive index profile in the coupling region is W-shaped.

Abstract: The present invention provides a controllable double cladding guiding structure for tunable phase delay, dynamic chromatic dispersion and polarization mode dispersion compensation. The device includes an etched fiber, an electro-optic material with index of refraction changing with externally applied stimulus (electric, magnetic or thermal effect) and a fiber Bragg grating (uniform, apodized, linearly or non-linearly chirped).

Abstract: Described is a composite liquid crystalline mixture having a low refractive index and a chemical reactive power that makes it capable of minimizing an anchoring energy when in contact with silica. This mixture comprises: (a) low ordinary refractive index nematic liquid crystal of a single type or a mixture of low ordinary refractive index nematic liquid crystals of different types; (b) at least one reagent compound capable of reducing the anchoring energy via a chemical shielding process and from which originates a decoupling effect with a glass interface leading to the reduction of the anchoring energy and appropriately orienting a liquid crystal director at this interface; and (c) at least one low refractive index additive having a relatively low viscosity. The above mixture is useful in waveguide tuning applications.

Abstract: We propose a dynamically tunable electro-optic cladding using our proprietary electro-optic material, applied to various circular and planar wave-guides along with specific electrode configuration and excitation electric field format appropriate to that material. Based on the evanescent field coupling phenomena, the proposed device may be used in variable optical attenuators, tunable filters and couplers, etc. Different design of applied electrodes and optical properties of controllable refractive index materials allow polarization dependent or independent, as well as direct or inverse operation regimes of proposed devices.

Abstract: Broadband polarization transformation devices of various constructions are provided. The devices of the invention include a plurality of polarization switching elements that are either wavelength insensitive or used only in a wavelength insensitive manner. Preferably, 90° or 45° twisted liquid crystal cells which are electrically switchable and achromatic birefringent elements (such as Fresnel Rhombs) are used. In a particularly advantageous embodiment, the device is composed of, consecutively, a 90°TLC cell, a 45°TLC cell, a Fresnel Rhomb and an additionnal 45° TLC cell, allowing an initially linearly polarized light beam to be switched between the output polarization states p, s, &sgr;, −&sgr;, 45° and −45° depending on the application of voltages on the TLC cells.

Abstract: A method and an apparatus for coupling a light emitting diode (LED) or another light source to an optical waveguide structure via removing a section of a LED resin case to expose a surface closely proximal to a light-emitting face of the semiconductor LED chip. An input end of the optical waveguide is mounted proximal and substantially perpendicular to the surface. The optical waveguide structure and the LED resin case are bonded by, in one embodiment of the invention, a light or thermally curable resin that is applied and further solidified. In a second embodiment of the invention, a photopolymer, sensitive to the light emerging from the waveguide, is used to bond the LED resin case and the optical waveguide structure. An automated coupling system is proposed to optimize the coupling conditions using the in-coupled light efficiency feedback and controller.

Abstract: A variable optical device for selectively controlling propagation of light within an optical waveguide. The optical device comprises: a relief modulation defining a grating disposed proximal the waveguide and having a respective grating index of refraction nG; a matrix surrounding at least the relief modulation, the matrix having an index of refraction nEO that is controllable, in response to a selected stimulus between a first value that is substantially equal to the grating index of refraction nG, and a second value that is different from nG; and at least one electrode for supplying the selected stimulus to the matrix-grating system.

Abstract: The present invention provides a controllable double cladding guiding structure for tunable phase delay, dynamic chromatic dispersion and polarization mode dispersion compensation. The device includes an etched fiber, an electro-optic material with index of refraction changing with externally applied stimulus (electric, magnetic or thermal effect) and a fiber Bragg grating (uniform, apodized, linearly or non-linearly chirped).

Abstract: We propose a dynamically tunable electro-optic cladding using our proprietary electro-optic material, applied to various circular and planar wave-guides along with specific electrode configuration and excitation electric field format appropriate to that material. Based on the evanescent field coupling phenomena, the proposed device may be used in variable optical attenuators, tunable filters and couplers, etc. Different design of applied electrodes and optical properties of controllable refractive index materials allow polarization dependent or independent, as well as direct or inverse operation regimes of proposed devices.