USA As Represented by Secretary of the Navy

Doewon Park

William S Rabinovich

Todd H Stievater

Marcel W Pruessner

Jacob B Khurgin

John Bradley Boos

Brian R Bennett

Walter Kruppa

Jonathan L Shaw

Bradford B Pate

James G Champlain

Rita Mahon

Dmitry A Kozak

Ming-Jey Yang

Kevin Jensen

J Brad Boos

Byoung-don Kong

Joan E Yater

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 device having: a substrate having a dielectric surface; a gate electrode; a drain electrode; a source electrode having a conductive contact and a two-dimensional material edge; and a dielectric material between the source and the gate. The source is adjacent to the gate. The drain electrode is not laterally between the edge and the gate electrode, and the distance from the drain electrode to the edge is greater than the distance from the gate electrode to the edge. The edge does not contact any other component of the device. The gate, drain, and source are not in electrical contact with each other. There is a line of sight or electron path from the edge to the drain electrode.

Vacuum transistor structure using graphene edge field emitter and screen electrode

A waveguide device for frequency mixing or conversion through birefringent phase matching, having a horizontal waveguide suspended above a substrate. The waveguide is formed of a zinc blend type III-V semiconductor material with a high nonlinear susceptibility.

Nonlinear frequency conversion in nanoslab optical waveguides

A waveguide device for frequency mixing or conversion through birefringent phase matching, having two suspended horizontal waveguides with an air-filled horizontal nanoslot between them. The waveguides are formed of a material with a high nonlinear susceptibility, and one waveguide can be n-doped with the other waveguide slab being p-doped. The system can be tuned to operate at different frequencies by varying the nanoslot gap distance by electrostatically actuating the suspended air-clad waveguides.

Nonlinear frequency conversion in nanoslot optical waveguides

Heterostructure field-effect transistors (HFETs) and other electronic devs are fabricated from a series of semiconductor layers to have reduced impact ionization. On to a first barrier layer there is added a unique second subchannel layer having high quality transport properties for reducing impact ionization. A third barrier layer having a controlled thickness to permit electrons to tunnel through the layer to the subchannel layer is added as a spacer for the fourth main channel layer. A fifth multilayer composite barrier layer is added which has at least a barrier layer in contact with the fourth channel layer and on top a sixth cap layer is applied. The device is completed by adding two ohmic contacts in a spaced apart relationship on the sixth cap layer with a Schottky gate between them which is formed in contact with the fifth barrier layer. The second subchannel layer and the fourth main channel layers are made of materials which have the proper respective energy gaps and ground state energies such that during use the transfer of hot electrons from the main channel into the subchannel is made probable to reduce impact ionization in the main channel. In the preferred AlSb/InAs-based HFETs, the use of an Is InAs subchannel layer under the main InAs channel improves the performance of the HEMTs particularly for gate lengths in the deep-submicron regime. The devices exhibit higher transconductance, lower output conductance, reduced gate leakage current, higher operating drain voltage, and improved frequency performance.

Channel design to reduce impact ionization in heterostructure

An electronic device characterized by a GaAs substrate and a base disposed n the substrate, the base comprising InAs channel layer, AlSb layer above the channel layer, In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer containing at least In, Al, and As disposed above the AlSb channel layer, InAs cap layer disposed above and in contact with the In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer disposed below the InAs channel layer and in contact with the substrate, p.sup.+ GaSb layer disposed within the AlSb layer, Schottky gate with a pad disposed on and in contact with the In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y layer, at least one ohmic contact disposed on the InAs cap layer, and a trench extending through the base to the substrate isolating the gate bonding pad from the device and providing a gate air bridge which prevents contact between the gate and the InAs layer. The gate air bridge fabrication is accomplished by a liquid etchant containing more than half, on volume basis, of concentrated lactic acid or acetic acid with remainder hydrogen peroxide and concentrated hydrofluoric acid. The etchant attacks InAs, In.sub.x Al.sub.1-x As.sub.y Sb.sub.1-y, AlSb, and GaSb but does not attack GaAs and Au-based alloys.

Electronic devices with InAlAsSb/AlSb barrier

Growing community of inventors

Herndon, VA, United States of America

Doewon Park