California Institute of Technology

Xponent Photonics Inc

Emcore Corporation

Hoya Corporation USA

Other

Optical Air Data Systems, LLC

Government of the United States of America, as Represented by the Secretary of Commerce

Hqphotonics Inc.

University of California

The United States of America

Johnston Pump/general Valve, Inc.

Encore Corporation

Kerry J Vahala

David W Vernooy

Henry A Blauvelt

Jiang Li

Oskar Jon Painter

Joel S Paslaski

Guido Hunziker

Xiaoguang He

Peter C Sercel

Hansuek Lee

Tong Chen

Philip L Rogers

Ming Cai

Scott A Diddams

Tobias J Kippenberg

Sean M Spillane

Scott E Fraser

Mani Hossein-Zadeh

Robert B Lee

Xu Yi

Roberto Paiella

Michael A Newkirk

Myoung-Gyun Suh

Lan Yang

Seung Hoon Lee

Deniz K Armani

Amnon Yariv

John E Bowers

Michael E Hoenk

David S Alavi

Tsu-Te Judith Su

Dong Yoon Oh

Andrea Martin Armani

Scott Brian Papp

Paul M Bridger

Kartik A Srinivasan

Tao Lu

Rajan P Kulkarni

Tal Eliezer Carmon

Andrea L Martin

Steve Sanders

Jay W Dawson

Yu-Hung Lai

Kiyoul Yang

Namkyoo Park

Scott Diddams

A disk resonator is pumped by counterpropagating pump signals to produce corresponding counterpropagating Brillouin laser signals. The pump laser optical frequencies are separated by a frequency offset &#x394;&#x3bd;but excite the same nominal resonator optical mode; the Brillouin laser optical frequencies are separated by a beat frequency &#x394;&#x3bd;with 0&#x3c;&#x394;&#x3bd;&#x3c;&#x394;&#x3bd;. A photodetector receives the Brillouin laser signals and produces an electrical signal at the beat frequency &#x394;&#x3bd;. The frequency offset &#x394;&#x3bd;can be large so enough to prevent locking of the Brillouin laser signals onto a common Brillouin laser frequency. A signal processing system derives from the beat frequency &#x394;&#x3bd;an estimated angular velocity component of the disk optical resonator about an axis substantially perpendicular to the disk optical resonator.

Stimulated brillouin ring laser gyroscope with optical frequency offset of counterpropagating pump laser signals

A ring optical resonator is formed on a substrate. An outer circumferential surface of the resonator substantially confines one or more circumferential resonant optical modes. The resonator is positioned above a void formed in the substrate and is supported above the void by a portion of a material layer on the substrate that extends radially inward above the void from an outer circumferential edge of the void to the outer circumferential surface of the resonator. An optical waveguide can be integrally formed on the substrate and traverses a portion of the material layer above the void. The optical waveguide and the ring optical resonator are arranged and positioned so as to establish evanescent optical coupling between them. Q-factors of 10or more have been achieved with a silica resonator and silicon nitride waveguide integrally formed on a silicon substrate.

High-Q optical resonator with monolithically integrated waveguide

A voltage-controlled oscillator generates a VCO output signal at frequency f. A dual optical-frequency source generates optical signals at frequencies vand v. An electro-optic frequency divider (EOFD) generates multiple optical sidebands spaced by f, and from two sidebands generates a beat signal at beat frequency &#x3b4;f. A first control circuit generates an error signal from the beat signal and a first reference signal at frequency f, and couples the VCO and the EOFD in a negative feedback arrangement that stabilizes the output frequency f. A second control circuit generates an error signal from the frequency-divided output signal and a second reference signal at frequency f, and couples the VCO and one or both of the dual source or the first reference signal in a negative feedback arrangement that stabilizes, or compensates for fluctuations of, a difference frequency v&#x2212;v.

Stabilized microwave-frequency source

A modulated semiconductor laser source includes a waveguide on a semiconductor substrate; first and second reflectors; a laser electrode; an optical modulator; and a laser-electrode electrical circuit. The reflectors and a resonator segment of the waveguide define a laser resonator with laser output transmitted through the second reflector. The laser electrode is positioned over the resonator segment and a laser current flows through the laser electrode into the resonator segment to produce optical gain. The modulator receives and modulates the laser output, in response to a primary modulation signal, to produce a modulated output optical signal. The laser-electrode circuit is coupled to the laser electrode and derives from the primary modulation signal a laser-electrode secondary modulation current, optimized to reduce chirp in the modulated output signal, that flows through the laser electrode into or out of the resonator segment in addition to the laser current.

Modulated laser source and methods of its fabrication and operation

A dual-comb optical-frequency comb generator includes a tunable comb-generating laser, a coarse-comb generator, a fine-comb generator, a second harmonic generator, a coarse-comb offset photodetector, a dual-comb offset photodetector, and a fine-comb photodetector. The coarse comb is self-referencing and coupled to the fine comb so as to enable absolute determination of the frequencies of the fine comb.

Optical frequency measurement and control using dual optical-frequency combs

A stabilized laser source includes a fiber-ring Brillouin laser that incorporates a circulator for non-reciprocal operation and for launching of a pump optical signal. Most of the pump optical signal is launched in a forward direction and drives Brillouin laser oscillation in the backward direction, a portion of which exits via an optical coupler as the optical output of the laser source. A small fraction of the pump optical signal is launched in the backward direction via the optical coupler, and a fraction of that backward-propagating pump optical signal exits via the optical coupler as an optical feedback signal. A frequency-locking mechanism receives the optical feedback signal and controls the pump optical frequency to maintain resonant propagation of the backward-propagating pump optical signal. A second pump optical signal can be launched in the forward direction to generate a second Brillouin laser oscillation.

Stabilized non-reciprocal fiber-ring brillouin laser source

A microwave-frequency source at frequency fcomprises: a dual optical-frequency reference source, an electro-optic sideband generator, an optical bandpass filter, an optical detector, a reference oscillator, an electrical circuit, and a voltage-controlled oscillator (VCO). The sideband generator modulates dual optical reference signals at vand vto generate sideband signals at v&#xb1;nfand v&#xb1;nf. The bandpass filter transmits sideband signals at v+Nfand v&#x2212;Nf. The optical detector generates a beat note at (v&#x2212;Nf)&#x2212;(v+Nf). The beat note and a reference oscillator signal are processed by the circuit to generate a loop-filtered error signal to input to the VCO. Output of the VCO at fdrives the sideband generator and forms the microwave-frequency output signal. The resultant frequency division results in reduced phase noise on the microwave-frequency signal.

Microwave-frequency signal generation by generating multiple sideband optical signals separated by phase-modulation frequency f, generating beat signals between one or two sidebands and one or two optical reference signals, generating a loop-filtered error signal by comparing an electrical reference signal to one of the beat signals or their difference, and controlling with the error signal in a phase-locked loop arrangement a voltage-controlled oscillator (VCO) that drives the sideband generation at the frequency f. A portion of the VCO output is the generated microwave-frequency signal.

Optical frequency divider based on an electro-optical-modulator frequency comb

A microwave-frequency source, generating an output electrical signal at an output frequency f, comprises a pump laser source, an optical resonator, and a photodetector. Free spectral range vof the optical resonator equals an integer submultiple of a Brillouin shift frequency vof the optical resonator (i.e., v=Mv). The pump laser source is frequency-locked to a corresponding resonant optical mode of the optical resonator. Pumping the optical resonator with output of the pump laser source at a pump frequency vresults in stimulated Brillouin laser oscillation in the optical resonator at respective first, second, and third Stokes Brillouin-shifted frequencies v=v&#x2212;v, v=v&#x2212;2v, and v=v&#x2212;3v. The photodetector receives stimulated Brillouin laser outputs at the first and third Stokes Brillouin-shifted frequencies vand vand generates therefrom the output electrical signal at a beat frequency f=v&#x2212;v=2v. The output electrical signal at the output frequency fexhibits exceptionally low phase noise.

Stable microwave-frequency source based on cascaded brillouin lasers

A semiconductor device comprising a substrate; a monolithic gain region disposed on the substrate and operable to produce optical gain in response to current injection, including a first electrode over a first portion of the gain region having a first length L, with a first current Ibeing applied; and a second electrode over a second portion of the gain region having a second length L, with a second current Ibeing applied; wherein I/Lis greater than I/L.

Method of fabricating and operating an optical modulator

A method of making an optical modulator by determining the material composition of the quantum well region in the waveguide portion of the modulator so that the modulator is transparent at a gain peak wavelength that is greater than the predetermined wavelength by a predetermined amount, and fabricating the modulator with the determined material composition.

A dual-frequency optical source comprises: (a) first and second pump laser sources arranged to generate optical pump power at respective first and second pump laser frequencies vand v; and (b) a fiber optical resonator characterized by a Brillouin shift frequency vand a free spectral range that is substantially equal to an integer submultiple of the Brillouin shift frequency. Each one of the first and second pump laser sources is frequency-locked to a corresponding resonant optical mode of the fiber optical resonator. First and second optical output signals of the dual-frequency optical reference source at respective first and second output frequencies v=v&#x2212;vand v=v&#x2212;vcomprise stimulated Brillouin laser output generated by simultaneous optical pumping of the fiber optical resonator by the first and second pump laser sources, respectively. An output difference frequency v&#x2212;vis greater than about 300 GHz.

Dual-frequency optical source

An optical modulator including an information-containing radio frequency signal input; a semiconductor device having an optical input optically for receiving the coherent light beam, and a electrode connected to said radio frequency signal input and having a modulated bias potential so that current is generated in the second semiconductor device and extracted therefrom, while the coherent light beam is optically modulated by the signal changing the carrier density in the semiconductor device.

Optical modulator

Growing community of inventors

San Gabriel, CA, United States of America

Kerry J Vahala