Massachusetts Institute of Technology

Raytheon Company

Anuradha Murthy Agarwal

Lionel Cooper Kimerling

Juejun Hu

Kazumi Wada

Jurgen Michel

Tian Gu

Derek Kita

Brian W Anthony

Robin Singh

Hongtao Lin

Frank B Jaworski

Junying Li

Pao Tai Lin

Danhao Ma

Michelle L Clark

Fleur Jacolien Fok

Eveline Postelnicu

Peter X Su

Samarth Aggarwal

Pradip Kumar Roy

Steven G Johnson

Adam M Kennedy

Darin Scot Williams

Hermann A Haus

Desmond Rodney Lim

Justin Gordon Adams Wehner

Xiaochen Sun

Daniel Knight Sparacin

Andrea Ivano Melloni

Christina Manolatou

Francesco Morichetti

Ning-Ning Feng

Antonio Canciamilla

Yan Cai

Jean Francois Viens

Victor Trinh Nguyen

Stefano Grillanda

Vivek Raghunathan

Drew Michael Weninger

Vivek Singh

Samuel Serna

Jianfei Wang

A photonic aerosol particle sensor includes a microfluidic sensor chamber in which is disposed a plurality of photonic waveguide resonators each having a photonic waveguide on an underlying substrate, along a separate waveguide resonator path with a lateral width different than that of other photonic waveguide resonators. All waveguides in the plurality have a common vertical thickness of a common waveguide material having a refractive index that is larger than that of the underlying substrate material. An optical input connection couples light into the waveguide resonators. An aerosol particle input fluidically connected to the microfluidic chamber fluidically conveys aerosol particles to the chamber, and an aerosol particle output fluidically connected to the microfluidic chamber fluidically conveys aerosol particles out of the chamber. At least one optical output connection accepts light out of the plurality of photonic waveguide resonators to provide a signal indicative of at least one aerosol particle characteristic.

Physical and chemical characterization of aerosols with photonic waveguides

A layer of amorphous Ge is formed on a substrate using electron-beam evaporation. The evaporation is performed at room temperature. The layer of amorphous Ge has a thickness of at least 50 nm and a purity of at least 90% Ge. The substrate is complementary metal-oxide-semiconductor (CMOS) compatible and is transparent at Long-Wave Infrared (LWIR) wavelengths. The layer of amorphous Ge can be used as a waveguide in chemical sensing and data communication applications. The amorphous Ge waveguide has a transmission loss in the LWIR of 11 dB/cm or less at 8 &#x3bc;m.

Amorphous germanium waveguides for spectroscopic sensing and data communication applications

A microscale photoacoustic sensor uses the detection of ultrasound waves generated by a sample in response to incident light absorption to perform photoacoustic spectroscopy, imaging, and microscopy. The microscale photoacoustic sensor, including components to excite a sample and detect ultrasound waves, may be integrated onto a single chip. The microscale photoacoustic sensor may excite a sample using a metasurface collimator. The metasurface collimator includes an array of diffraction grooves to collimate an excitation beam uniformly out of the plane of the sensor to create a wide and homogeneous beam spot. The microscale photoacoustic sensor may detect ultrasound waves using an optical photoacoustic transducer. The optical photoacoustic transducer includes a resonator on a mechanical membrane to detect ultrasound waves with high sensitivity. The microscale photoacoustic sensor may be used in applications such as deep-tissue neural imaging or microfluidic biological screening.

Microscale photoacoustic spectroscopy, imaging, and microscopy

A photonic aerosol particle sensor includes a plurality of photonic waveguide resonators each having a photonic waveguide disposed along a separate waveguide resonator path and each photonic waveguide having a lateral waveguide width different than the waveguide width of other photonic waveguide resonators in the plurality. All waveguides in the plurality of photonic waveguide resonators have a common vertical thickness and are formed of a common photonic waveguide material. An optical input connection couples light into the waveguide resonators. A particle input conveys aerosol particles toward the waveguide resonators and an aerosol particle output conveys aerosol particles away from the waveguide resonators. At least one optical output connection is optically connected to accept light out of the plurality of photonic waveguide resonators to provide a signal indicative of at least one characteristic of the aerosol particles to be analyzed.

Optical interconnects can offer higher bandwidth, lower power, lower cost, and higher latency than electrical interconnects alone. The optical interconnect system enables both optical and electrical interconnection, leverages existing fabrication processes to facilitate package-level integration, and delivers high alignment tolerance and low coupling losses. The optical interconnect system provides connections between a photonics integrated chip (PIC) and a chip carrier and between the chip carrier and external circuitry. The system provides a single flip chip interconnection between external circuitry and a chip carrier using a ball grid array (BGA) infrastructure. The system uses graded index (GRIN) lenses and cross-taper waveguide couplers to optically couple components, delivers coupling losses of less than 0.5 dB with an alignment tolerance of &#xb1;1 &#x3bc;m, and accommodates a 2.5&#xd7; higher bandwidth density.

Simultaneous electrical and optical connections for flip chip assembly

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Apparatus, systems, and methods for on-chip spectroscopy using optical switches

An apparatus for generating a spectral image includes a filter to receive incident light. The filter has a variable refractive index. The apparatus also includes a modulator, operably coupled to the filter, to modulate the variable refractive index of the filter so as to generate a plurality of optical patterns from the incident light. The plurality of optical patterns represents the spectral image and each optical pattern in the plurality of optical patterns corresponds to a different modulation of the variable refractive index. The apparatus further includes a detector, in optical communication with the filter, to detect the plurality of optical patterns.

Methods and apparatus for spectral imaging

A device includes a substrate, a pedestal extending from the substrate, and a ring resonator disposed on the pedestal above the substrate. The ring resonator has a resonance wavelength greater than 1.5 &#x3bc;m and includes at least one of silicon and chalcogenide glass. The device can be used as a ring resonator sensor or a light source. The ring resonator is substantially transparent to mid-infrared radiation to reduce optical losses. The pedestal has a narrower width compared to the ring resonator to generate improved interaction between evanescent fields of light in the ring resonator and analytes nearby the ring resonator, thereby increasing sensing sensitivity. In addition, fabrication of the device is compatible with complementary metal-oxide-semiconductor (CMOS) processes and hence is amenable to large scale manufacturing.

Methods and apparatus for pedestal ring resonators

In a photonic waveguide, there is provided an undercladding layer and a waveguide core, having a cross-sectional height and width, that is disposed on the undercladding layer. The waveguide core comprises a waveguide core material having a thermo-optic coefficient. A refractive index tuning cladding layer is disposed on top of the waveguide core. The refractive index tuning cladding layer comprises a refractive index tuning cladding material having an adjustable refractive index and an absorption length at a refractive index tuning radiation wavelength. A thermo-optic coefficient compensation cladding layer is disposed on top of the refractive index tuning cladding layer. The thermo-optic coefficient compensation cladding layer comprises a thermo-optic coefficient compensation material having a thermo-optic coefficient that is of opposite sign to the thermo-optic coefficient of the waveguide core material. The thermo-optic coefficient compensation cladding layer provides at least partial compensation for the waveguide core thermo-optic coefficient.

Athermal photonic waveguide with refractive index tuning

A chip-scale, air-clad semiconductor pedestal waveguide can be used as a mid-infrared (mid-IR) sensor capable of in situ monitoring of organic solvents and other analytes. The sensor uses evanescent coupling from a silicon or germanium waveguide, which is highly transparent in the mid-IR portion of the electromagnetic spectrum, to probe the absorption spectrum of fluid surrounding the waveguide. Launching a mid-IR beam into the waveguide exposed to a particular analyte causes attenuation of the evanescent wave's spectral components due to absorption by carbon, oxygen, hydrogen, and/or nitrogen bonds in the surrounding fluid. Detecting these changes at the waveguide's output provides an indication of the type and concentration of one or more compounds in the surrounding fluid. If desired, the sensor may be integrated onto a silicon substrate with a mid-IR light source and a mid-IR detector to form a chip-based spectrometer.

Methods and apparatus for mid-infrared sensing

In certain embodiments, a system for detecting an agent includes a resonator device configured to receive an agent. The resonator device is also configured to transmit light received from a light source, the transmitted light having an altered peak wavelength due to the presence of the received agent. The system further includes a filter device configured to filter the transmitted light having the altered peak wavelength such that the transmitted light having the altered peak wavelength does not reach one or more detectors of a detector array configured to receive transmitted light not filtered by the filter device. The system further includes a processing system operable to determine that the one or more detectors of the detector array are not generating a signal, the absence of the signal being generated by the one or more detectors of the detector array indicating the presence of the agent.

Optical device for detection of an agent

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Weston, MA, United States of America

Anuradha Murthy Agarwal