Leland Stanford Junior University

Other

Oregon State University

Imra America, Inc.

New Focus, Inc.

Ntt Research, Inc.

Microtech Instruments, Inc.

Martin M Fejer

Robert L Byer

Michel J F Digonnet

Gregory David Miller

Lawrence E Myers

Yannick G Feillens

Eric J Lim

Mark Alan Arbore

Jonathan R Kurz

Donald J Harter

Herbert J Shaw

Almantas Galvanauskas

Shoichi Sudo

Konstantin L Vodopyanov

Ming-Hsien Chou

Robert G Batchko

Gregory A Magel

Leslie A Gordon

Michael Digonnet

Celestino Gaeta

Michel J Digonnet

James S Harris, Jr

Amado Cordova

Vladimir G Kozlov

Kenneth A Fesler

Aharon Kapitulnik

Robert S Feigelson

Robert H Hammond

Malcolm R Beasley

John L Nightingale

Michael Louis Bortz

Hubert S Stokowski

Marc P Jankowski

Cordova Amado

Vladimir Shur

Whu-ming Young

Hiroshi Noguchi

Andreas Sizmann

Stephan Schiller

Yun-Shik Lee

Christopher B Ebert

Weizhi Wang

Steven J Benerofe

Loren A Eyres

Charles H Ahn

Krishnan Parameswaran

Marc David Levenson

Jatadhari Mishra

Marc Jankowski

Alexander Y Hwang

Timothy P McKENNA

Amir H Safavi-naeini

Robert C Eckardt

Carsten Langrock

In some embodiments, a device for generating mid-infrared radiation is provided. The device may include a thin film quadratic nonlinear waveguide formed on a mid-infrared transparent cladding by a thin film material of a predetermined film thickness, the waveguide having a predetermined etch depth and a predetermined top width. At least one of the predetermined film thickness, the predetermined etch depth, and the predetermined top width may be tuned for the device to generate a coherent idler wave as a mid-infrared radiation from a fixed pump wave and a tunable signal wave.

Ultra-broadband mid-infrared generation in dispersion-engineered thin-film lithium niobate

Improved efficiency for nonlinear optical interactions is provided by using strongly confining waveguides for simultaneous imposition of dispersion design constraints at two or more dispersion orders. Quasi-phase-matching allows for phase-matching to be accomplished independently of the waveguide design, which helps provide sufficient design freedom for the dispersion design.

Nonlinear optical devices based on quasi-phase-matched interactions in dispersion-engineered nanophotonics

Terahertz radiation generation systems and methods are implemented using a variety of methods and devices. According to an example embodiment of the present invention, method for generating terahertz radiation is implemented where the wavelength of an optical pulse is controlled, and where the wavelength is controlled as a function of the group velocity dispersion in a nonlinear crystal. The optical pulse is then directed through consecutively-inverted parallel domains in the nonlinear crystal.

Terahertz radiation generation and methods therefor

A method for generating THz radiation comprises illuminating a semiconductor crystal with an optical pulse train. The semiconductor crystal comprises alternating parallel crystal domains, with each domain having a crystal orientation inverted with respect to adjacent domains. The optical pulse train propagates substantially perpendicularly relative to domain boundaries in the semiconductor crystal. The THz radiation is generated from the optical pulse train by optical down-conversion mediated by the semiconductor crystal. Optical path lengths through the crystal domains at least in part determine a frequency of the generated THz radiation. THz generation efficiency may be enhanced by placing the semiconductor crystal within an external resonant cavity, by placing the semiconductor crystal within a laser cavity, or by placing the semiconductor crystal within an OPO cavity. The semiconductor crystal may comprise zinc-blende, III-V, or II-VI semiconductor.

Generation of terahertz radiation in orientation-patterned semiconductors

A multi-channel optical frequency mixer for all-optical signal processing and a method for engineering the same. The multi-channel mixer uses a nonlinear optical material exhibiting an effective nonlinearity dwhose spatial distribution is defined by a quasi-phase-matching grating, e.g., a QPM grating. The spatial distribution is defined such that its Fourier transform to the spatial frequency domain defines at least two wavelength channels which are quasi-phase-matched for performing optical frequency mixing. The wavelength channels correspond to dominant Fourier components and the Fourier transform is appropriately adjusted using grating parameters such as grating periods, phase reversal sequences and duty cycles to include an odd or even number of dominant Fourier components. The multi-channel mixer can perform frequency mixing operations such as second harmonic generation (SHG), difference frequency generation (DFG), sum frequency generation (SFG), and parametric amplification.

Multiple channel optical frequency mixers for all-optical signal processing

In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped BiGeOmaterial). The optical input signals include optical signals having wavelengths over a range of approximately 125. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the approximately 125-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

Method of amplifying optical signals using doped materials with extremely broad bandwidths

An apparatus and method for nonlinear frequency mixing of light waves relying on a nonlinear material having a nonlinear coefficient d and a waveguide fabricated in the nonlinear material. The waveguide is equipped with a quasi-phase-matching (QPM) grating extending along the length of the waveguide and endowed with an asymmetry of the nonlinear coefficient d along the width of the waveguide. The transverse asymmetry is chosen to establish a mode overlap for nonlinear frequency mixing between different transverse width modes of light. The transverse asymmetry can be odd or else neither odd nor even so as to establish mode overlap for frequency mixing between even transverse width modes and odd transverse width modes. The QPM grating can have single or multiple grating stripes that can be staggered, interleaved, angled and otherwise altered to achieve the transverse asymmetry establishing a mode overlap for frequency mixing between even transverse width modes and odd transverse width modes.

Apparatus and method for quasi-phase-matched nonlinear frequency mixing between different transverse width modes

A method and a nonlinear frequency mixer employing the method to generate at least one output light from at least one input light with the aid of a quasi-phase-matching (QPM) grating for quasi-phase-matching the input and output light involved in a nonlinear frequency mixing operation such as three-wave mixing, four-wave mixing or other nonlinear operation mediated by a susceptibility of the nonlinear optical material. The QPM grating has a beam-modifying pattern with features for wave front shaping. More specifically, the features shape the wave fronts of the output light by diffraction or phase front shaping to thereby modify its propagation. This modification of propagation can be used to steer, focus, defocusing, split and/or collimate the output light. The features themselves can have various geometric shapes and sizes, even on the order of the wavelength of the output light, and they can include domains exhibiting a nonlinear optical susceptibility &#x3c7;, such as the second-order susceptibility &#x3c7;, domain edges, and/or spacings between such domains.

Nonlinear frequency mixer using quasi-phase-matching gratings having beam-modifying patterns

In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped SrY(SiO)O material). The optical input signals include optical signals having wavelengths over a range of approximately 125 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over approximately a 125-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end of the range.

In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths over a range of at least 80 nanometers, and, preferably, over a range of at least 160 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the extended 80-160-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

A multiple-wavelength ultrashort-pulse laser system includes a laser generator producing ultrashort pulses at a fixed wavelength, and at least one and preferably a plurality of wavelength-conversion channels. Preferably, a fiber laser system is used for generating single-wavelength, ultrashort pulses. An optical split switch matrix directs the pulses from the laser generator into at least one of the wavelength conversion channels. An optical combining switch matrix is disposed downstream of the wavelength-conversion channels and combines outputs from separate wavelength-conversion channels into a single output channel. Preferably, waveguides formed in a ferroelectric substrate by titanium indiffusion (TI) and/or proton exchange (PE) form the wavelength-conversion channels and the splitting and combining matrices. Use of the waveguide allows efficient optical parametric generation to occur in the wavelength-conversion channels at pulse energies achievable with a mode-locked laser source. The multiple-wavelength laser system can replace a plurality of different, single-wavelength laser systems. In its simplest form, the system can be used to convert the laser wavelength to a more favorable wavelength. For example, pulses generated at 1.55 &mgr;m by a mode-locked erbium fiber laser can be converted to 1.3 &mgr;m for use in optical coherence tomography or to wavelengths suitable for use in a display, printing or machining system.

Ultrashort-pulse source with controllable wavelength output

A compensated nonlinear optical frequency mixer for compensating the walk-off produced by group velocity mismatch (GVM) between interaction waves. The compensated mixer has a first mixing region in which the interaction waves participate in a non-linear optical mixing process and where walk-off occurs between the interaction waves due to GVM. The compensated mixer is equipped with a frequency selective coupling and time delay structure located after the first mixing region for eliminating the walk-off produced between the interaction waves in the first mixing region by guiding the waves in arms whose lengths differ by a re-synchronization length. A second mixing region is located after the frequency-selective coupling and time delay structure, such that when the waves emerge in phase from the frequency selective coupling and time delay structure they continue to interact efficiently in the second mixing region. The compensated nonlinear optical frequency mixer of the invention can by used to compensate for GVM in frequency mixing operations involving a material's &khgr; susceptibility.

Group-velocity mismatch compensation for optical signal processing

A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. The waveform then lowers the voltage such that the electric field has a value at which a domain wall velocity is most sensitive to changes in the field. The waveform maintains the electric field value until a current through the substrate drops substantially. The electric field is then lowered to a value below a level required to sustain domain wall motion, but greater than a level below which backswitching occurs. The electric field is then lowered to zero in such a way as to prevent backswitching. Alternatively, the electric field is maintained for a time t determined by t&equals;x/v, where x is a domain wall half-width and v is a domain wall velocity. Subsequently, the waveforms lower the voltage to zero.

Method for fabricating efficient sources of electromagnetic radiation

A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. Domain reversal continues through to completion at which time the poling field is turned off or substantially reduced to induce spontaneous backswitch poling. The forward poling field is then reapplied to stop the backswitch poling. The ability to selectively enable and terminate backswitching allows for the formation of domain patterns with small feature sizes and high uniformity through large volumes of material.

Backswitch poling method for domain patterning of ferroelectric materials

Growing community of inventors

Menlo Park, CA, United States of America

Martin M Fejer