Massachusetts Institute of Technology

Omniguide Communications

Harvard College

Omniguide, Inc.

US Government As Represented by the Secretary of the Army

Cornell University

University of Central Florida Research Foundation, Inc.

Princeton University

Steven G Johnson

John Dimitris Joannopoulos

Marin Soljacic

Mihai Ibanescu

Yoel Fink

Ori Weisberg

Maksim Skorobogatiy

Torkel Engeness

Shanhui Fan

Steven Alan Jacobs

Alejandro W Rodriguez

Michelle L Povinelli

George Barbastathis

Hermann A Haus

Leslie Kolodziejski

Lori Pressman

Wesley A King

Evan J Reed

Emilia G Anderson

Rokan Ahmad

Alexei A Erchak

Elefterios Lidorikis

Marko Loncar

Chiyan Luo

Pierre R Villeneuve

Erich P Ippen

Suraj Deepak Bramhavar

Max Shurgalin

Jeffrey Scott Herd

Gale Petrich

Ivan Celanovic

Christina Manolatou

Cheryl Marie Sorace-Agaskar

Nuh Gedik

Boris G Kharas

Michael A Shapiro

Jamison Sloan

Liang Jie Wong

Solomon Assefa

Samuel Kim

Byron Freelon

Timm Rohwer

John D Joannopolous

Xiangdong Liang

Josue Lopez

David R Liu

Federico Capasso

Michael Robert Watts

Lionel Cooper Kimerling

Michal Lipson

Klavs F Jensen

Kazumi Wada

Jurgen Michel

Anuradha Murthy Agarwal

Chee Wei Wong

Yichen Shen

Ayman F Abouraddy

Peter Thomas Rakich

Sang-Gook Kim

Esmaeil Banaei

Peter H Fisher

Peter Bienstman

Burak Temelkuran

Tairan Wang

Uri Kolodny

Rafif E Hamam

Michael Ghebrebrhan

Soroush Shabahang

Peter Bermel

Daosheng S Deng

Guangming Tao

Lucas Heitzmann Gabrielli

Marco Piccardo

Joshua J Kaufman

Adrian Y X Yeng

Walker Chan

Gokhan Ulu

Robert Pilawa-Podgurski

Victor Trinh Nguyen

Jorge Bravo-Abad

Zin Lin

Yinan Zhang

James Goell

Hila Hashemi

Dexin Ye

Reginald E Bryant

John D Joannopoious

Maksim Skorobagatiy

Maksim Skorobogatly

Paul Chevalier

Arman Amirzhan

Fan Wang

Henry O Everitt

Christopher Marton

Mohammad Araghchini

Ardavan Farjadpour

John D Joanopoulos

Ian B Burgess

Murray W McCutcheon

Disclosed is a laser system including a first laser and a second laser. The first laser includes a laser cavity, and a gas phase molecular gain medium disposed in the laser cavity, the gain medium having an absorption band. The second laser is a solid state laser configured to be continuously tunable, with respect to an emission wavelength of the second laser, over the absorption band of the gain medium, and the second laser is tuned to pump rotational vibrational transitions in the gain medium to achieve a rotational population inversion.

Widely tunable compact terahertz gas lasers

An integrated optical beam steering device includes a planar Luneburg lens that collimates beams from different inputs in different directions within the lens plane. It also includes a curved (e.g., semi-circular or arced) grating coupler that diffracts the collimated beams out of the lens plane. The beams can be steered in the plane by controlling the direction along which the lens is illuminated and out of the plane by varying the beam wavelength. Unlike other beam steering devices, this device can operate over an extremely wide field of view&#x2014;up to 180&#xb0;&#x2014;without any aberrations off boresight. In other words, the beam quality is uniform in all directions, unlike with aplanatic lenses, thanks to the circular symmetry of the planar Luneburg lens, which may be composed of subwavelength features. The lens is also robust to misalignment and fabrication imperfections and can be made using standard CMOS processes.

Planar Luneburg lens system for two-dimensional optical beam steering

A fully confined dual frequency optical resonator configured for optical coupling to light having a first frequency &#x3c9;. The dual frequency optical resonator includes a plurality of alternating layer pairs configured in a grating configuration, each layer pair having a first layer formed of a first material and a second layer formed of a second material, the first material and second material being different materials. Each layer having a thickness different than a thickness of an adjacent layer to provide thereby aperiodic layer pairs, the thicknesses of adjacent layers being selected to create, via wave interference with each layer, optical resonances at the first frequency &#x3c9;and a second frequency &#x3c9;which is a harmonic of &#x3c9;, and to ensure a maximum spatial overlap between confined modes over the materials such that an overall quality factor Q of at least 1000 is achieved.

Multi-mode cavities for high-efficiency nonlinear wavelength conversion formed with overlap optimization

A filter to transmit incident radiation at a predetermined incidence angle includes a plurality of photonic crystal structures disposed substantially along a surface normal direction of the filter. The photonic crystal structure includes a multilayer cell that comprises a first layer having a first dielectric permittivity, and a second layer having a second dielectric permittivity different from the first dielectric permittivity. The first layer and the second layer define a Brewster angle substantially equal to the predetermined incidence angle based on the first dielectric permittivity and the second permittivity. Each photonic crystal structure in the plurality of photonic crystal structures defines a respective bandgap, and the respective bandgaps of the plurality of photonic crystal structures, taken together, cover a continuous spectral region of about 50 nm to about 100 mm.

Methods and apparatus for broadband angular selectivity of electromagnetic waves

Methods and apparatus for modulating a particle pulse include a succession of Hermite-Gaussian optical modes that effectively construct a three-dimensional optical trap in the particle pulse's rest frame. Optical incidence angles between the propagation of the particle pulse and the optical pulse are tuned for improved compression. Particles pulses that can be modulated by these methods and apparatus include charged particles and particles with non-zero polarizability in the Rayleigh regime. Exact solutions to Maxwell's equations for first-order Hermite-Gaussian beams demonstrate single-electron pulse compression factors of more than 100 in both longitudinal and transverse dimensions. The methods and apparatus are useful in ultrafast electron imaging for both single- and multi-electron pulse compression, and as a means of circumventing temporal distortions in magnetic lenses when focusing ultra-short electron pulses.

Systems and methods for particle pulse modulation

A fiber is provided, including a cladding material that is disposed along a longitudinal-axis fiber length. A plurality of spherical particles are disposed as a sequence along a longitudinal line parallel to the longitudinal fiber axis in at least a portion of the fiber length, and include a spherical particle material that is interior to the fiber cladding material and different than the fiber cladding material. To produce particles, a drawn fiber, having a longitudinal-axis fiber length and including at least one fiber core that has a longitudinal core axis parallel to the longitudinal fiber axis and that is internally disposed to at least one outer fiber cladding layer along the fiber length, is heated for a time that is sufficient to cause a fiber core to break-up into droplets sequentially disposed along the fiber core axis. Fiber cooling solidifies droplets into spherical particles interior to fiber cladding.

In-fiber particle generation

Inventive systems and methods for the generation of energy using thermophotovoltaic cells are described. Also described are systems and methods for selectively emitting electromagnetic radiation from an emitter for use in thermophotovoltaic energy generation systems. In at least some of the inventive energy generation systems and methods, a voltage applied to the thermophotovoltaic cell (e.g., to enhance the power produced by the cell) can be adjusted to enhance system performance. Certain embodiments of the systems and methods described herein can be used to generate energy relatively efficiently.

Thermophotovoltaic energy generation

A fiber structure for propagating one or more zero group-velocity modes is provided. The fiber structure includes a cladding arrangement comprising a photonic crystal having a complete bandgap at a specified index. A core is formed in a selective region of the cladding arrangement. The core allows the propagation of the one or more group-velocity modes.

Zero group-velocity modes in chalcogenide holey photonic crystal fibers

Techniques and devices are disclosed to provide controlled inter-mode cross-talk in multimode optical waveguides. The structure of a bent multimode optical waveguide can be designed or configured in a way that either substantially minimizes inter-mode cross talk or achieves a desired inter-mode cross-talk. Specific examples based on the disclosed waveguide designs are provided for semiconductor integrated waveguide devices.

Controlled inter-mode cross-talk in optical waveguides

A system for efficient generation of THz radiation is provided that includes a triply-resonant nonlinear photonic resonator coupled to at least one near-infrared (NIR) or optical waveguide and to at least one THz waveguide. The energy traveling through the at least one near-infrared (NIR) or optical waveguide is converted to THz radiation inside the triply-resonant photonic resonator via a nonlinear difference frequency generation (DFG) process.

Efficient terahertz sources based on difference-frequency generation in triply-resonant photonic resonators

In general, in a first aspect, the invention features photonic crystal fibers that include a core extending along a waveguide axis, a confinement region extending along the waveguide axis surrounding the core, and a cladding extending along the waveguide axis surrounding the confinement region, wherein the cladding has an asymmetric cross-section.

Photonic crystal fibers having a preferred bending plane and systems that use such fibers

A nonlinear harmonic generation system is provided. The nonlinear harmonic generation system includes a waveguide channel receives and propagates electromagnetic signals. A resonant cavity is coupled to the waveguide channel. The resonant cavity structure includes a plurality of resonant modes into which electromagnetic energy is coupled during the operation of the system. One of the resonant modes includes a resonant frequency that changes during operation of the system to reach either an input-signal frequency or a harmonic frequency for a majority of the time in which harmonic generation is occurring. Both reflected and harmonic fields are emitted back into the waveguide channel so as to allow efficient harmonic generation at a specified critical input power.

Nonlinear harmonic generation and devices in doubly-resonant Kerr cavities

A doubly-resonant cavity structure includes at least one cavity structures so as to allow total frequency conversion for second or third-harmonic generation using &#x3c7;and &#x3c7;nonlinearities between the at least one cavity structures. The total frequency conversion is efficiently optimized by determining a critical power allowing for such total frequency conversion to occur depending on the cavity parameters of the at least one cavity structures.

Efficient harmonic generation and frequency conversion in multi-mode cavities

Growing community of inventors

Cambridge, MA, United States of America

Steven G Johnson