Abstract: A fuel cell membrane electrode assembly including a polymer electrolyte membrane (PEM) and first and second electrodes. The PEM is situated between the first and second electrodes. The first electrode includes a first catalyst material layer including a first catalyst material and having first and second surfaces. The first electrode includes first and second material layers adjacent to the first and second surfaces, respectively, of the first catalyst material. The first material layer faces away from the PEM and the second material layer faces the PEM. The first material layer comprises a graphene-based material layer having a number of defects configured to mitigate dissolution of the first catalyst material through the first material layer.

Abstract: An optical grating coupler includes a primary layer formed of a material having a first refractive index. A first plurality of scattering elements is formed within the primary layer. The first plurality of scattering elements has a second refractive index that is different than the first refractive index. A secondary layer is formed over the primary layer. The secondary layer is formed of a material having a third refractive index. A second plurality of scattering elements is formed within the secondary layer. The second plurality of scattering elements has a fourth refractive index that is different than the third refractive index. The fourth refractive index is different than the second refractive index. At least some of the second plurality of scattering elements at least partially overlap corresponding ones of the first plurality of scattering elements.

Abstract: An optical switch includes a bus waveguide supported by a substrate, an actuation electrode supported by the substrate, the actuation electrode having fins that protrude in a direction perpendicular to the substrate and to the bus waveguide, and a reaction electrode having interdigitated fins configured to form a comb drive with the actuation electrode. When a voltage difference between the reaction electrode and the actuation electrode is less than a lower threshold, the reaction electrode is positioned a first distance from the bus waveguide, when the voltage difference between the reaction electrode and the actuation electrode is greater than an upper threshold, the reaction electrode is positioned a second distance from the bus waveguide, and the second distance is less than the first distance.

Abstract: An optical switch includes a bus waveguide supported by a substrate, an actuation electrode supported by the substrate, the actuation electrode having fins that protrude in a direction perpendicular to the substrate and to the bus waveguide, and a reaction electrode having interdigitated fins configured to form a comb drive with the actuation electrode. When a voltage difference between the reaction electrode and the actuation electrode is less than a lower threshold, the reaction electrode is positioned a first distance from the bus waveguide, when the voltage difference between the reaction electrode and the actuation electrode is greater than an upper threshold, the reaction electrode is positioned a second distance from the bus waveguide, and the second distance is less than the first distance.

Abstract: A fuel cell membrane electrode assembly including a polymer electrolyte membrane (PEM) and first and second electrodes. The PEM is situated between the first and second electrodes. The first electrode includes a first catalyst material layer including a first catalyst material and having first and second surfaces. The first electrode includes first and second material layers adjacent to the first and second surfaces, respectively, of the first catalyst material. The first material layer faces away from the PEM and the second material layer faces the PEM. The first material layer comprises a graphene-based material layer having a number of defects configured to mitigate dissolution of the first catalyst material through the first material layer.

Abstract: A method for fabricating an optical device and micromechanical device, wherein both devices are monolithically-integrated with a substrate. The optical surfaces and micromechanical devices are each formed in an etch step that is well-suited for forming that device. In addition, the embodiments of the present invention enable the optical surface and micromechanical device to be fabricated irrespective of severe topography on the surface of the substrate.

Abstract: A method for fabricating an optical device and micromechanical device, wherein both devices are monolithically-integrated with a substrate. The optical surfaces and micromechanical devices are each formed in an etch step that is well-suited for forming that device. In addition, the embodiments of the present invention enable the optical surface and micromechanical device to be fabricated irrespective of severe topography on the surface of the substrate.

Abstract: A method of fabricating a self-aligned vertical combdrive is described. The method includes the steps of etching in a semiconductor wafer a first comb with a coarse set of teeth. A second semiconductor wafer is bonded to the first set of teeth. A set of accurately positioned teeth is etched in the second wafer with teeth overlapping the teeth in the first comb. The lower teeth are etched using the overlapping teeth as a mask to assure proper alignment. One variation in this fabrication method whereby the first coarse comb teeth are etched on semiconductor-on-insulator instead, allows creation of double-sided comb actuators with increased torsional deflection range. Another variation to this fabrication method that keeps the electrically isolated upper masking teeth allows creation of dual-mode vertical comb actuators after an initial assembly step.

Abstract: One embodiment of the present invention provides a spatial light phase modulator, which can perform piecewise linear phase modulation of a light beam. This spatial light phase modulator includes an array of movable micromirrors and an array of actuators. Each actuator of the array of actuators is movably coupled to one micromirror of the array of movable micromirrors and can move the micromirror both vertically and rotationally. Additionally, the present invention provides an optical function generator that is a femtosecond pulse shaper. This optical function generator includes a diffraction grating that disperses an input pulse into a dispersed spectrum, a lens assembly to focus the dispersed spectrum onto a micromirror array, and the micromirror array to provide spatial filtering to the dispersed spectrum to provide the filtered spectrum.

Abstract: One embodiment of the present invention provides a spatial light phase modulator, which can perform piecewise linear phase modulation of a light beam. This spatial light phase modulator includes an array of movable micromirrors and an array of actuators. Each actuator of the array of actuators is movably coupled to one micromirror of the array of movable micromirrors and can move the micromirror both vertically and rotationally. Additionally, the present invention provides an optical function generator that is a femtosecond pulse shaper. This optical function generator includes a diffraction grating that disperses an input pulse into a dispersed spectrum, a lens assembly to focus the dispersed spectrum onto a micromirror array, and the micromirror array to provide spatial filtering to the dispersed spectrum to provide the filtered spectrum.