Abstract: A method of optimizing the coupling to an optical fiber, including: generating a femtosecond laser pulse; directing a focus of the laser pulse to a longitudinal depth in the region beneath the endface of the optical fiber to generate microvoids; adjusting the intensity of the laser pulse at different depths, such that a refractive index profile is created in the region beneath the endface of the optical fiber.

Abstract: An optical material including: a silica host; and a Praseodymium dopant; wherein the Praseodymium atoms are configured to form nanoclusters in the silica host. In addition, the optical material may include an Ytterbium co-dopant. The nanoclusters include Ge, Te, Ta, Lu and/or F, Cl to minimize multi-phonon quenching. Moreover, the nanoclusters may be encapsulated in a low phonon energy shell to minimize energy transfer to the host matrix.

Abstract: A method of optimizing the coupling to an optical fiber, including: generating a femtosecond laser pulse; directing a focus of the laser pulse to a longitudinal depth in the region beneath the endface of the optical fiber to generate microvoids; adjusting the intensity of the laser pulse at different depths, such that a refractive index profile is created in the region beneath the endface of the optical fiber.

Abstract: An optical material including: a silica host; and a Praseodymium dopant; wherein the Praseodymium atoms are configured to form nanoclusters in the silica host. In addition, the optical material may include an Ytterbium co-dopant. The nanoclusters include Ge, Te, Ta, Lu and/or F, Cl to minimize multi-phonon quenching. Moreover, the nanoclusters may be encapsulated in a low phonon energy shell to minimize energy transfer to the host matrix.

Abstract: Disclosed is a method of fabricating an optical waveguide device including the steps of forming a mask over a waveguide core material layer so as to leave a portion of the layer exposed, and exposing the structure to an oxidizing environment to form an oxide layer on the waveguide core material layer at least in the exposed portion thereby defining the lateral dimension of the waveguide core. The resulting waveguide core has extremely smooth surfaces for low optical losses.

Abstract: A thermo-optic device and a method for using it are described. The device has a substrate including a pair of waveguides coupled at first and second coupling regions. At the first coupling region, an input signal is split between the two waveguides. Between the coupling regions on one of the waveguides is a demultiplexer, at least one phase shifting device, and a multiplexer. The signal portions recombine at the second coupling region. Heater strips at the first and second coupling regions alter the temperature at the first and second coupling regions, in response to applied control signals, thereby adjusting the insertion loss and dynamic range of the device. A sensor samples an output signal from the substrate and sends a signal to a controller, which controls the phase shifting devices and the heater strip to maintain the output signal within predetermined signal parameters.

Abstract: The present invention provides an optoelectronic device with superior qualities. The optoelectronic device includes an optical core feature located over a substrate, an outer cladding layer located over the optical core feature and a direct patch mask formed on an outer cladding layer. In an exemplary embodiment of the invention, the direct patch mask has a light source passed therethrough that corrects birefringence in the optical core feature and the outer cladding layer.

Abstract: The present invention provides an optoelectronic device with superior qualities. The optoelectronic device includes an optical core feature located over a substrate, an outer cladding layer located over the optical core feature and a direct patch mask formed on an outer cladding layer. In an exemplary embodiment of the invention, the direct patch mask has a light source passed therethrough that corrects birefringence in the optical core feature and the outer cladding layer.

Abstract: A thermo-optic device and a method for using it are described. The device has a substrate including a pair of waveguides coupled at first and second coupling regions. At the first coupling region, an input signal is split between the two waveguides. Between the coupling regions on one of the waveguides is a demultiplexer, at least one phase shifting device, and a multiplexer. The signal portions recombine at the second coupling region. Heater strips at the first and second coupling regions alter the temperature at the first and second coupling regions, in response to applied control signals, thereby adjusting the insertion loss and dynamic range of the device. A sensor samples an output signal from the substrate and sends a signal to a controller, which controls the phase shifting devices and the heater strip to maintain the output signal within predetermined signal parameters.

Abstract: An apparatus and method for reducing the power needed to operate a thermo-optic switch using a heat sensitive optical phase shifter which is controlled by an electrically powered metal heater strip attached to the optical waveguide of the phase shifter. The power can be reduced by reducing the thickness of the upper cladding to 15 microns or less, increasing the thickness of the lower cladding to more than 15 microns, and adjusting the index contrast (&Dgr;) of the materials comprising the upper cladding, the lower cladding, and the core of the waveguide so that it is greater than 0.4%.

Abstract: A refractory dielectric body is heated with a plasma fireball at conditions which do not result in substantial removal of a surface portion of the body, yet which are sufficient to reduce both surface and bulk impurities. Typically, the body is treated with the plasma in the absence of simultaneous deposition of material onto the body. Advantageously, an isothermal, oxygen or oxygen-containing plasma is utilized. The invention is useful for reducing chlorine impurities by at least about 30% to a depth of at least about 10 .mu.m, with accompanying reduction of hydroxyl impurities. The invention thus provides a useful method for reducing the concentration of impurities that contribute to imperfections during the process of drawing fiber from an optical fiber preform, without requiring substantial removal of the surface of the preform.

Abstract: A refractory dielectric body is heated with a plasma torch at conditions which do not result in substantial removal of a surface portion of the body, yet which are sufficient to reduce both surface and bulk impurities. Typically, the body is solid, e.g., a rod as opposed to a tube, and is treated with the plasma in the absence of simultaneous deposition of material onto the body. Advantageously, an isothermal plasma torch is utilized, and the torch advantageously produces an oxygen or oxygen-containing plasma. The invention is useful for reducing chlorine impurities by at least about 30% to a depth of at least about 10 .mu.m, with accompanying reduction of hydroxyl impurities. The invention thus provides a useful method for reducing the concentration of impurities that contribute to imperfections during the process of drawing fiber from an optical fiber preform, without requiring substantial removal of the surface of the preform.

Abstract: A method and apparatus are provided for forming a glass preform which can be directly drawn into a single or multi-mode optical fiber. Single or multi-mode fibers drawn from the preforms described herein have high quality core-clad interfaces since the core and cladding materials are not exposed to crystallization temperatures upon the addition of the core material to cladding material.

Abstract: A method and apparatus are provided for forming a glass preform which can be directly drawn into a single or multi-mode optical fiber. Single or multi-mode fibers drawn from the preforms described herein have high quality core-clad interfaces since the core and cladding materials are not exposed to crystallization temperatures upon the addition of the core material to cladding material.

Abstract: A method and apparatus are provided for forming a glass preform which can be directly drawn into a single or multi-mode optical fiber. Single or multi-mode fibers drawn from the preforms described herein have high quality core-clad interfaces since the core and cladding materials are not exposed to crystallization temperatures upon the addition of the core material to cladding material.