Leland Stanford Junior University

Michel Jf Digonnet

Gordon S Kino

Shanhui Fan

Olav Solgaard

Aydogan Ozcan

Onur Can Akkaya

Onur Kilic

Vinayak Dangui

Hyang Kyun Kim

Shrestha Basu Mallick

Seth Lloyd

Jonghwa Shin

Behrad Habib Afshar

An acoustic sensor includes at least one optical waveguide configured to emit an optical beam, a substantially planar first substrate optically coupled to the at least one optical waveguide, and a substantially planar second substrate substantially parallel to the first substrate, affixed to the first substrate, and affixed to the at least one optical waveguide. The first substrate is configured to be illuminated by the optical beam and to reflect at least a portion of the optical beam to the at least one optical waveguide. The first substrate includes a first substrate portion configured to reflect a first portion of the optical beam back to the at least one optical waveguide and a diaphragm configured to reflect a second portion of the optical beam back to the at least one optical waveguide. The diaphragm is responsive to a perturbation by moving relative to the first substrate portion. The optical beam is centered on a region between the first substrate portion and the diaphragm.

Self-aligning optical acoustic sensors

A sensor includes at least one optical waveguide and an optical reflector optically coupled to the at least one optical waveguide. The optical reflector includes a first substrate portion configured to reflect a first portion of a light beam back to the at least one optical waveguide and a diaphragm configured to reflect a second portion of the light beam back to the at least one optical waveguide. The diaphragm is responsive to a perturbation by moving relative to the first substrate portion. The light beam is centered on a region between the first substrate portion and the diaphragm.

Diaphragm-based fiber acoustic sensor

An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical waveguide having a length and a laser source optically coupled to the waveguide. The laser source has a coherence length. Light from the source is transmitted to the waveguide as a first signal propagating along the waveguide in a first direction and a second signal propagating along the waveguide in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the waveguide to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.

Optical sensor having a non-negligible source coherence length

A method for measuring a physical function forms a symmetric composite function by combining the physical function with a reference function. The method obtains a Fourier transform of the symmetric composite function. The method calculates an inverse Fourier transform of the obtained Fourier transform, wherein the calculated inverse Fourier transform provides information regarding the physical function. The physical function can be a nonlinearity profile of a sample with at least one sample surface. The physical function can alternatively by a sample temporal waveform of a sample optical pulse.

Method of measuring a physical function using a composite function which includes the physical function and an arbitrary reference function

A method measures a nolinearity profile of a sample with at least one sample surface and having a sample nonlinearity profile along a sample line through a predetermined point on the sample surface. The sample line is oriented perpendicularly to the sample surface. The method includes measuring a Fourier transform of the sample nonlinearity profile and obtaining a reference nonlinearity profile from a reference material. The method includes forming a first composite sample having a first composite nonlinearity profile and forming a second composite sample having a second composite nonlinearity profile inequivalent to the first composite nonlinearity profile. The method further includes measuring a Fourier transform of the first composite nonlinearity profile and measuring a Fourier transform of the second composite nonlinearity profile. The method further includes calculating the sample nonlinearity profile using the Fourier transforms of the sample nonlinearity profile, the reference nonlinearity profile, the first composite nonlinearity profile, and the second composite nonlinearity profile.

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Palo Alto, CA, United States of America

Michel Jf Digonnet