Massachusetts Institute of Technology

The Charles Stark Draper Laboratory, Inc.

Other

Polaroid Corporation

The Charles Stark Draper Lab., Inc.

Farhad Hakimi

Hosain Hakimi

Richard P Tumminelli

John R Haavisto

Katherine L Hall

Elias Snitzer

Hong Po

Kristin A Rauschenbach

Daniel T Moriarty

William A Dyes

Moungi G Bawendi

Robert P Dahlgren

Jesse Tawney

Methods and apparatus are provided for integrating various optical components onto a planar substrate using a single semiconductor material system to produce an accelerometer. A light beam is generated on the semiconductor optical accelerometer. The light beam is split to form two light beams using a multimode interference (MMI) coupler. One of the two light beams that is formed is directed towards a reference mirror and the other is directed towards a flexured mirror. The flexured mirror moves as a result of acceleration and thereby reflects the light beam with a different light beam characteristic. The light beams are combined by the MMI coupler to produce an interference light beam. A microprocessor measures acceleration based on the differences in light beam characteristics of the reflected light beams. Along the optical path light beam detectors measure various beam characteristics. The microprocessor accounts for characteristics measured by the detectors when computing acceleration.

Methods and apparatus for providing a semiconductor optical flexured mass accelerometer

A process shifts wavelengths of optical pulses. The process includes transmitting an incoming optical pulse through a nonlinear optical material, splitting the transmitted pulse into a plurality of mutually coherent optical pulses, and recombining the mutually coherent pulses with temporal delays. The recombined pulses produce a temporal interference pattern. The pattern has a peak whose wavelength is shifted with respect to the wavelength of the incoming optical pulse.

Fast optical wavelength shifter

A method introduces variable time offsets into a stream of optical pulses. The method includes receiving a plurality of coherent optical pulses, receiving a plurality of control signals, and forming a coherent pulse array (CPA) from each pulse in response to one of the received control signals. Temporal spacings between pulses of each CPA are responsive to the associated one of the received control signals. For optical control signals, response times can be very short. The method further includes transmitting each pulse through a dispersive optical medium. The act of transmitting makes pulses of each CPA overlap to form an interference pattern.

Fast variable optical delay

A method produces a wavelength shift into an optical signal. The method includes producing a coherent temporal array of optical signals (CTAS) from an incoming optical signal and broadening the signals of the CTAS to produce a interference pattern. The broadening results from transmitting the CTAS or the incoming optical signal through a dispersive medium. The method also includes selectively transmitting a peak of the interference pattern. The transmitted peak has a selected wavelength shift with respect to the incoming optical signal.

Wavelength shifting and optical switching

A method of transmitting optical pulses in a transmission media includes separating a coherent source optical pulse into a plurality of mutually coherent pulses, and producing a series of mutually coherent optical pulses from the plurality of pulses. The series is transmitted through the media, and the pulses of the series are received at a distant region of the media. The series of pulses is adapted to interfere and form a packet whose width is narrower than the width of any pulse of the series at the distant region.

Quasi-dispersionless optical fiber transmission, dispersion compensation and optical clock

A method of generating a signal including: generating a first sequence of coherent optical pulses which are sufficiently close in spacing so as to overlap and interfere upon traveling a predetermined length down an optical fiber to form a first interference pattern with a first central lobe having a characteristic wavelength, wherein the energy of the pulses of the first sequence of pulses is within the non-linear regime of the optical fiber; manipulating the first sequence of optical pulses; in a similar manner generating a second sequence of coherent optical pulses; manipulating the second sequence of optical pulses; and introducing both the first and second manipulated sequences of pulses into the optical fiber, wherein the manipulating of the pulses of the first and the second sequence of pulses shifts the characteristic wavelengths of the first and second central lobes, respectively, to first and second transmission signal wavelengths.

WDM system that uses nonlinear temporal gratings

A method of generating a signal pulse in an optical fiber characterized by dispersion and a refraction index that has a nonlinear regime of operation, the method including generating a sequence of coherent optical pulses each of which has an associated energy; and introducing the sequence of pulses into the optical fiber, wherein the pulses in the sequence of pulses are sufficiently close in spacing so that after traveling a predetermined length down the optical fiber, the pulses of the sequence of pulses overlap and interfere to form an interference pattern, and wherein the associated energy of at least one of the pulses of the sequence of pulses is within the nonlinear regime of the optical fiber.

Nonlinear temporal grating as a new optical solitary wave

An optical amplifier includes first and second optical fibers. The first optical fiber has a core, a first cladding surrounding the core and a second cladding surrounding the first cladding. The second optical fiber has an end physically coupled to a side portion of the first optical fiber. The end transmits light to the first cladding.

Side pumped optical amplifiers and lasers

A dental device for removable placement in the mouth of a user for eliminating snoring and relieving stress. The device includes and upper member which is adapted for engagement with the user's upper dentition. An anterior extension suspends downwardly from the upper member and includes an interior surface and an exterior surface. The exterior surface is configured based on the user's jaw and mouth anatomy so that the exterior surface engages at least some of the lower front teeth in the user's mouth. Engagement of the exterior surface of the anterior extension with the user's lower front teeth advances the user's jaw forward with respect to the user's upper jaw such that the user's upper airway is enlarged and the passage of air though the upper airway is facilitated. The interior surface of the anterior extension is advantageously provided with a rough texture for attracting and positioning the tongue in a forward position. The upper member also includes a support member which lies proximate the hard palate in the user's mouth and has a rearwardly extending posterior portion configured to engage the soft palate of the user to complement the forward advancement of the user's lower jaw and open the user's upper airway to reduce vibration of the soft tissues in the upper airway which cause snoring.

Snore and stress relieving device

Chromatic and polarization dispersion and transmitter frequency chirp are the dominant data rate limiting factors for high-speed, long distance communication systems. To overcome such limitations, a chromatic and polarization dispersion and frequency chirp compensator is utilized. The applicants provide a compensator by combining a wavelength to polarization transformer with a polarization to delay converter having a dispersion characteristic of substantially equivalent in magnitude, and opposite in sign, to the desired amount of dispersion and frequency chirp to be compensated. Optical gain may be incorporated in any of the elements of the compensator which makes the present invention a lightwave amplifier as well as a dispersion compensator. The present invention is also applicable as an optical pulse time compressor that compresses a relatively long width optical pulse to a short width pulse.

Apparatus for compensating chromatic and polarization dispersion and

Apparatus for depolarizing light in fiber optics, comprises of a pair of fiber optic collimators and plurality of contiguous slabs of linear birefringent plates arranged in a stack forming a parallel slab. The optical axes of said linear birefringent plates are approximately 45 degrees with respect to each other. Thicknesses of said linear birefringent plates are such that their individual polarization mode delays exceed coherence time of a beam defined by an optical source.

Fiber optic depolarizer for optical time domain reflectometer and fiber

A scattered light Moire-Brillouin guided wave gyroscope includes a coherent light source for providing two counter-rotating primary waves; an optical waveguide, responsive to the two primary waves, for generating a Moire fringe from a primary fringe and a Brillouin fringe derived respectively from the counter-rotating primary waves and from the counter-rotating Brillouin waves produced from the primary waves; and means for detecting the rotation of the Moire fringe relative to the waveguide.

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Watertown, MA, United States of America

Farhad Hakimi