Abstract:
A change in mass of a microbridge in a mass sensor can be sensed by applying a time-varying amplitude modulated electrostatic force to excite the microbridge into resonance at the frequency of amplitude modulation. An optical energy is then transmitted at a wavelength close to a resonant wavelength of a Fabry-Perot microcavity, which is formed by etching a movable reflective mirror into a region of the microbridge and by etching a fixed reflective minor in a region spaced apart from the microbridge. The two mirrors are interconnected by an optical waveguide. The movable mirror and fixed mirror reflect the optical energy to a receiver, and a change in the Fabry-Perot microcavity's reflectivity is interferometrically determined. The change in reflectivity indicates a change in the microbridge's resonant frequency due to increased mass of the microbridge resulting from sorption of a target chemical by a layer of chemoselective material deposited on the microbridge.
Abstract:
An optically addressed spatial light modulator includes top and bottom conductive layers sandwiching an intrinsic semiconductor multilayer structure. A cladding layer having a high trapping density is sandwiched between at least one of the electrodes and the intrinsic semiconductor layer structure. Typically, one cladding layer will be sandwiched between the top conductive layer and the intrinsic semiconductor multilayer structure and another cladding layer will be sandwiched between the bottom conductive layer and the intrinsic semiconductor structure. The cladding layer or layers laterally confine the photocarriers generated within the intrinsic semiconductor multilayer structure.
Abstract:
A solid-state laser device includes a neodymium laser pump source capable outputting a pump beam of about 1.1 .mu.m wavelength, and a holmium laser being pumped by said 1.1 .mu.m pump beam to generate an output laser beam of about 3 .mu.m wavelength.
Abstract:
A method and system described for sensing a displacement by receiving and propagating a laser light signal with an etched waveguide that is configured to enable an evanescent optical field above the waveguide surface. A movable perturber can be positioned so the perturber interacts with the evanescent optical field above the waveguide surface. An optical phase shift can be induced in the waveguide when the movable perturber is displaced in the evanescent optical field, and the optical phase shift can be measured with an optical readout circuit.
Abstract:
A mass sensor system including multiple Fabry-Perot microcavities connected in parallel by multiple waveguides. Each of the mass sensors includes a microbridge having a fundamental resonance frequency, and a movable reflective mirror etched into the microbridge; a fixed reflective mirror etched in a substrate, the fixed reflective mirror being fixed to the substrate in a region spaced apart from the movable reflective mirror; and an optical waveguide etched in the substrate that connects the movable mirror and the fixed mirror forming the Fabry-Perot microcavity interferometer. The system includes a tunable continuous-wave laser operative to optically interrogate the Fabry-Perot microcavity of each of the plurality of mass sensors, and a receiver operative to receive sensor signals from each of the plurality of mass sensors, the sensor signals comprising reflective signals and transmitted signals. A continuous-wave laser may generate optical forces that modify the motion, dynamics, or mechanical Q-factor of the microbridge.
Abstract:
A mass sensor system including multiple Fabry-Perot microcavities connected in parallel by multiple waveguides. Each of the mass sensors includes a microbridge having a fundamental resonance frequency, and a movable reflective mirror etched into the microbridge; a fixed reflective mirror etched in a substrate, the fixed reflective mirror being fixed to the substrate in a region spaced apart from the movable reflective mirror; and an optical waveguide etched in the substrate that connects the movable mirror and the fixed mirror forming the Fabry-Perot microcavity interferometer. The system includes a tunable continuous-wave laser operative to optically interrogate the Fabry-Perot microcavity of each of the plurality of mass sensors, and a receiver operative to receive sensor signals from each of the plurality of mass sensors, the sensor signals comprising reflective signals and transmitted signals. A continuous-wave laser may generate optical forces that modify the motion, dynamics, or mechanical Q-factor of the microbridge.
Abstract:
A mass sensor system including multiple Fabry-Perot microcavities connected in parallel by multiple waveguides. Each of the mass sensors includes a microbridge having a fundamental resonance frequency, and a movable reflective mirror etched into the microbridge; a fixed reflective mirror etched in a substrate, the fixed reflective mirror being fixed to the substrate in a region spaced apart from the movable reflective mirror; and an optical waveguide etched in the substrate that connects the movable mirror and the fixed mirror forming the Fabry-Perot microcavity interferometer. The system includes a tunable continuous-wave laser operative to optically interrogate the Fabry-Perot microcavity of each of the plurality of mass sensors, and a receiver operative to receive sensor signals from each of the plurality of mass sensors, the sensor signals comprising reflective signals and transmitted signals. A continuous-wave laser may generate optical forces that modify the motion, dynamics, or mechanical Q-factor of the microbridge.
Abstract:
Micro-opto-mechanical chemical sensors and methods for simultaneously detecting and discriminating between a variety of vapor-phase analytes. One embodiment of the sensor is a photonic microharp chemical sensor with an array of closely spaced microbridges, each differing slightly in length and coated with a different sorbent polymer. The microbridges can be excited photothermally, and the microbridges can be optically interrogated using microcavity interferometry. Other actuation methods include piezoelectric, piezoresistive, electrothermal, and magnetic. Other read-out techniques include using a lever arm and other interferometric techniques.
Abstract:
An electro-optic device with a doped semiconductor base and a plurality of pixels on the semiconductor base. Pixels include oppositely doped semiconductor layer and a top electrode formed on the oppositely doped semiconductor layer. The top electrode has a grid pattern with at least one busbar and a plurality of fingers extending from the busbar, and spacing between the fingers decreases with distance from the bondpad along the busbar. Each pixel can also include a multiple quantum well formed on the semiconductor base. The top electrode shape produces an approximately uniform lateral resistance in the pixel. An embodiment is a large area modulator for modulating retro-reflector systems, which typically use large area surface-normal modulators with large lateral current flow. Uniform resistance to each part of the modulator decreases location dependence of frequency response. A chirped grid electrode balances semiconductor sheet resistance and metal line resistance components of the series resistance.
Abstract:
An electro-optic device with a doped semiconductor base and a plurality of pixels on the semiconductor base, each pixel including: a multiple quantum well formed on the semiconductor base, an oppositely doped semiconductor layer on the multiple quantum well, and a top electrode on the semiconductor layer, the top electrode shaped to produce an approximately uniform lateral resistance in the pixel. An embodiment is a large area modulator for modulating retro-reflector systems, which typically use large area surface-normal modulators with large lateral current flow. Uniform resistance to each part of the modulator decreases location dependence of frequency response. A chirped grid electrode balances semiconductor sheet resistance and metal line resistance components of the series resistance.