Axsun Technologies, Inc.

Excelitas Technologies Corp.

Massachusetts Institute of Technology

Nirrin Technologies, Inc.

Other

University System of Maryland

Walid A Atia

Dale C Flanders

Mark E Kuznetsov

Bartley C Johnson

Peter S Whitney

Randal A Murdza

Petros Amestis Kotidis

Carlos R Melendez

Jeffrey A Korn

James W Getz

David O Caplan

Christopher C Davis

Minh Van Le

Brian Goldberg

Bryan Hassell

Eric E Fitch

Saeed Pilevar

Edward J Mallon

David P Marchessault

Klaus Edinger

Xinfa Ma

James Zambuto

Igor I Smolyaninov

Christopher C Cook

Xiaomei Wang

Steven David Conover

Robert K Jenner

Robert L Payer

Yu Nathan Li

Sean P O'Connor

Mark R Malonson

Lawrence McDermott

Walter R Buchwald

L James Newman, Iii

Christopher R Saulnier

John C Ho

Bart Ley C Johnson

A method for studying cell viability and protein aggregation involves establishing a Fabry Perot etalon signal within an optical spectroscopic feature, e.g., in the near infrared region. Protein aggregation and cell viability can be reflected by changes observed in the magnitude of the Fourier Transform peaks observed in the frequency or space domain associated with the contrast of the etalon. In short, the presence of viable cells and protein aggregates can degrade the etalon contrast of an etalon window. In some cases, the concentration of cells and monomeric protein can be measured as well.

Fabry Perot interferometry for measuring cell viability

An optically pumped tunable VCSEL swept source module has a VCSEL and a pump, which produces light to pump the VSCEL, wherein the pump is geometrically isolated from the VCSEL. In different embodiments, the pump is geometrically isolated by defocusing light from the pump in front of the VCSEL, behind the VCSEL, and/or by coupling the light from the pump at an angle with respect to the VCSEL. In the last case, angle is usually less than 88 degrees. There are further strategies for attacking pump noise problems. Pump feedback can be reduced through (1) Faraday isolation and (2) geometric isolation. Single frequency pump lasers (Distributed feedback lasers (DFB), distributed Bragg reflector lasers (DBR), Fabry-Perot (FP) lasers, discrete mode lasers, volume Bragg grating (VBG) stabilized lasers can eliminate wavelength jitter and amplitude noise that accompanies mode hopping.

Optically pumped tunable VCSEL employing geometric isolation

A device for monitoring a bioreactor is configured for in-situ analysis, e.g., by NIR, without the need for withdrawing a sample into a sample cell or into an ex-situ arrangement. The device can be inserted into a port of the bioreactor and provides a sample detection region defined by an optical element such as a lens and a photodetector. The electrical signal obtained from a photodetector that is part of the device can be directed to an analyzer via a detachable electrical connection.

In-situ probe

Quantum well designs for tunable VCSELs are disclosed that are tolerant of the wavelength shift. Specifically, the active region has even number of substantially uniformly spaced (&#xbc; of the center wavelength in the semiconducting material) quantum wells.

Quantum well placement in a tunable VCSEL

A design and method for introducing asymmetric crystal strain to control polarization in a tunable VCSEL, either optically or electrically pumped. The invention is especially relevant to wafer- or die-bonded tunable VCSELs. Then, mechanical stress is applied to the half VCSEL device by asymmetric arrangement of metal bond pads.

Tunable VCSEL polarization control through dissimilar die bonding

A microelectromechanical systems (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) in which the MEMS mirror is bonded to the active region. This allows for a separate electrostatic cavity that is outside the laser's optical resonant cavity. Moreover, the use of this cavity configuration allows the MEMS mirror to be tuned by pulling the mirror away from the active region. This reduces the risk of snap down. Moreover, since the MEMS mirror is now bonded to the active region, much wider latitude is available in the technologies that are used to fabricate the MEMS mirror. This is preferably deployed as a swept source in an optical coherence tomography (OCT) system.

OCT system with bonded MEMS tunable mirror VCSEL swept source

A frequency swept laser source for TEFD-OCT imaging includes an integrated clock subsystem on the optical bench with the laser source. The clock subsystem generates frequency clock signals as the optical signal is tuned over the scan band. Preferably the laser source further includes a cavity extender in its optical cavity between a tunable filter and gain medium to increase an optical distance between the tunable filter and the gain medium in order to control the location of laser intensity pattern noise. The laser also includes a fiber stub that allows for control over the cavity length while also controlling birefringence in the cavity.

Optical coherence tomography laser with integrated clock

An optical coherence analysis system uses a laser swept source that is constrained to operate in a stable mode locked condition by modulating a drive current to the semiconductor optical amplifier as function of wavelength or synchronously with the drive voltage of the laser's tunable element based on stability map for the laser.

System and method for stabilizing mode locked swept laser for OCT medical imaging

An integrated swept wavelength optical source uses a filtered ASE signal with an optical amplifier and tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a first tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal, and a second tunable Fabry Perot filter, installed on the bench, for spectrally filtering the amplified tunable signal from the amplifier. A self-tracking arrangement is also possible where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of a single bench implementation yields a low cost high performance system. For example, polarization control between components is no longer necessary.

Filtered ASE swept source for OCT medical imaging

An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal for form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm. In embodiments, the swept sources are tunable lasers that have shared laser cavities.

Integrated dual swept source for OCT medical imaging

An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal to form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm.

Integrated dual swept source alternating same scan band for OCT medical imaging

Growing community of inventors

Lexington, MA, United States of America

Walid A Atia