USA As Represented by Secretary of the Navy

Dmitry A Kozak

Todd H Stievater

R Andrew McGill

Marcel W Pruessner

Jacob B Khurgin

William S Rabinovich

Robert Furstenberg

Doewon Park

Brian J Roxworthy

Christopher Breshike

Scott A Holmstrom

Methods and apparatuses for mode conversion. An apparatus that includes a substrate, a first waveguide, a second waveguide, a micro-electro-mechanical systems (MEMS) perturber, and a controller is provided. The first waveguide is formed on the substrate includes: (i) an input section, (ii) a bend section, and (iii) an output section. The second waveguide is also formed on the substrate and is disposed adjacent to a portion of the input section of the first waveguide. A portion of the second waveguide is separated from the input section of the first waveguide by a coupling gap. The perturber is disposed above the first waveguide and configured to move between a first position that is distal from a surface of the input section of the first waveguide and a second position that is closer to the surface of the input section of the first waveguide than the second position. The controller is configured to control a movement of the perturber between the first position and the second position. When the perturber is in the first position, a mode effective refractive index of the first waveguide is lower than the mode effective refractive index of the first waveguide when the perturber is in the second position.

Methods and apparatuses for optical mode conversion

Presented herein is a new concept of uniformly spin coating a flat surface with a stationary phase and creating a gas chromatography column by pressing a grooved lid, with micro-stamped ridges, down onto the coated substrate. The lids are molded out of commercially available rigid materials including epoxies so that when pressed onto a flat surface it will create an air tight seal. The epoxy material is rendered inert by a thin layer of gold.

Spin coated stationary phase microfabricated gas chromatographic columns

Optical detectors and methods of forming them are provided. The detector includes: a controller, pump and probe laser generators that generate modulated pump laser and probe lasers, respectively, a microring cavity that receives the lasers, a microbridge, and a photodetector. The microring cavity includes covered and exposed portions. The microbridge is suspended above the exposed portion and interacts with an evanescent optical field. The wavelength and modulated power of the pump laser are controlled to generate the evanescent optical field that excites the microbridge to resonance. The microbridge absorbs optical radiation which changes the resonance frequency proportionately. The probe laser is modulated in proportion to a vibration amplitude of the microbridge to form a modulated probe laser which is provided to the photodetector. The controller receives data from the photodetector, determines a change in resonance frequency, and calculates the amount of absorbed radiation from the change in resonance frequency.

Methods and apparatuses for measuring optical radiation

A system and method for detecting an analyte includes a waveguide configured to receive a narrow-band laser signal; and a sorbent material covering an analyte detection region of the waveguide, wherein the sorbent material is configured to sorb the analyte and bring the analyte to an evanescent field of the waveguide, and wherein Raman scattering is produced by an interaction of the evanescent field and the analyte sorbed in the sorbent material along the analyte detection region of the waveguide, and the waveguide is further configured to collect the Raman scattering along the analyte detection region of the waveguide, wherein the collected Raman scattering indicates a type of the analyte.

Waveguide-enhanced Raman scattering spectroscopy of analytes using sorbents

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Berwyn Heights, MD, United States of America

Dmitry A Kozak