Abstract: Systems, methods, and mechanisms for sound beam focal point determination within an acoustic medium may include propagating a first sound beam to intersect a second sound beam, where the second sound beam converges at a focal point. The first and second sound beams may originate from known locations. A direction of the first sound beam within the acoustic medium may be adjusted to produce a maximum amplitude of signals generated from nonlinear mixing of the first sound beam and the second sound beam, where the maximum amplitude may correspond to the intersection of the first sound beam with the focal point of the second sound beam. A location of the intersection may be determined, at least in some instances, based on the known locations, the adjusted direction of the first sound beam, and a direction of the second sound beam.

Abstract: Systems, methods, and mechanisms for sound beam focal point determination within an acoustic medium may include propagating a first sound beam to intersect a second sound beam, where the second sound beam converges at a focal point. Signals representative of sound pressure in the acoustic medium may be received from one or more sensors. A direction and/or focal length of the first sound beam within the acoustic medium may be adjusted, based, at least in part, on the received signals, to produce a maximum amplitude of signals generated from nonlinear mixing of the first sound beam and the second sound beam, where the maximum amplitude may correspond to the intersection of the first sound beam with the focal point of the second sound beam. A location of the intersection may be determined, at least in some instances, using a time-of-arrival analysis on the received signals.

Abstract: In one aspect, an apparatus is disclosed comprising: a housing; a proof mass movable within the housing; an optical element mounted on one of the housing and the proof mass; a reflective element on the other one of the housing and the proof mass; a light source configured to illuminate grating and minor; and one or more detectors configured to detect light incident from the reflective element and the diffractive element and generate a signal indicative of the relative displacement of proof mass and the housing.

Abstract: In one aspect, an apparatus is disclosed comprising: a housing; a proof mass movable within the housing; an optical element mounted on one of the housing and the proof mass; a reflective element on the other one of the housing and the proof mass; a light source configured to illuminate grating and minor; and one or more detectors configured to detect light incident from the reflective element and the diffractive element and generate a signal indicative of the relative displacement of proof mass and the housing.

Abstract: Method for performing signal processing for an optical microphone. First and second signals corresponding to at least two beams may be generated or received. The first and second signals may be complementary, and may be based on signals provided by one or more photo detectors that receive the at least two beams after the beams return from a sensing structure. The first signal and the second signal may be subtracted to produce a third signal. A position of the sensing structure may be adjusted to cause the third signal to reach a first value, where the adjusting may be performed based on the third signal, and an audio output signal may be provided based on the third signal.

Abstract: An optical microphone that may include a first substrate with one or more acoustic entry ports and a die over the one or more acoustic entry ports. The die may include a sensing structure for detecting acoustic vibrations received via the acoustic entry port(s) and may form a first cavity between the first substrate and the sensing structure. The microphone may include a light source within the first cavity, which may transmit laser light. The optical microphone may include photo detector(s) within the first cavity. The one or more photodetectors may be configured to receive the laser light after reflection from the sensing diaphragm to measure the acoustic vibrations of the sensing diaphragm. The microphone may also include a circuit and a lid, where the die, light source, photo detectors, and circuit are comprised within the cavity of the microphone. The circuit may perform signal processing signals from the photodetector(s).

Abstract: An optical microphone that may include a first substrate with one or more acoustic entry ports and a die over the one or more acoustic entry ports. The die may include a sensing structure for detecting acoustic vibrations received via the acoustic entry port(s) and may form a first cavity between the first substrate and the sensing structure. The microphone may include a light source within the first cavity, which may transmit laser light. The optical microphone may include photo detector(s) within the first cavity. The one or more photodetectors may be configured to receive the laser light after reflection from the sensing diaphragm to measure the acoustic vibrations of the sensing diaphragm. The microphone may also include a circuit and a lid, where the die, light source, photo detectors, and circuit are comprised within the cavity of the microphone. The circuit may perform signal processing signals from the photodetector(s).

Abstract: An optical microphone that may include a first substrate with one or more acoustic entry ports and a die over the one or more acoustic entry ports. The die may include a sensing structure for detecting acoustic vibrations received via the acoustic entry port(s) and may form a first cavity between the first substrate and the sensing structure. The microphone may include a light source within the first cavity, which may transmit laser light. The optical microphone may include photo detector(s) within the first cavity. The one or more photodetectors may be configured to receive the laser light after reflection from the sensing diaphragm to measure the acoustic vibrations of the sensing diaphragm. The microphone may also include a circuit and a lid, where the die, light source, photo detectors, and circuit are comprised within the cavity of the microphone. The circuit may perform signal processing signals from the photodetector(s).

Abstract: Micron-scale displacement measurement devices having enhanced performance characteristics are disclosed. One embodiment of a micron-scale displacement measurement device includes a phase-sensitive reflective diffraction grating for reflecting a first portion of an incident light and transmitting a second portion of the incident light such that the second portion of the incident light is diffracted. The device can further include a mechanical structure having a first region and a second region, the mechanical structure positioned a distance d above the diffraction grating and forming a wall of a cavity, the second portion of the incident light is reflected off of the first region of the structure such that an interference pattern is formed by the reflected first portion and the reflected second portion of the incident light. The device can further include an orifice formed in the cavity to provide for the passage of air between the inside and outside of the cavity.

Abstract: Optical sensors, and methods for operating optical sensors, are disclosed. One such sensor may include: a reflector positioned a distance from a reflective diffraction grating and a light source for providing light. A first portion of the light can be reflected from the reflective diffraction grating and a second portion of the light passes through the grating to the reflector and is reflected back through the diffraction grating. The sensor may further include a detector for sensing an intensity of light in an interference pattern formed by the first portion of the light reflected from the diffraction grating and the second portion of the light reflected from the reflector. The sensor includes a controller configured to modulate an emission of the light.

Abstract: Micron-scale displacement measurement devices having enhanced performance characteristics are disclosed. One embodiment of a micron-scale displacement measurement device includes a phase-sensitive reflective diffraction grating for reflecting a first portion of an incident light and transmitting a second portion of the incident light such that the second portion of the incident light is diffracted. The device further includes a mechanical structure having a first region and a second region, the mechanical structure positioned a distance d above the diffraction grating, the second portion of the incident light is reflected off of the first region of the structure such that an interference pattern is formed by the reflected first portion and the reflected second portion of the incident light. The device can further include an electrode extending toward, but spaced a distance away from, the second region of the mechanical structure.

Abstract: The present invention relates to micron-scale displacement measurement devices. A first embodiment is a device that includes a substrate and a rigid structure suspended above the substrate to form a backside cavity. Formed in the rigid structure is a reflective diffraction grating positioned to reflect a first portion of an incident light and transmit a second portion of the incident light such that the second portion of the incident light is diffracted. The device also includes a membrane positioned a distance d above the reflective diffraction grating and at least a first photo-detector for receiving interference patterns produced from the first portion of the incident light reflected from the diffraction grating and the second portion of the incident light reflected from the membrane.

Abstract: The present invention relates to micron-scale displacement measurement devices. A first embodiment is a device that includes a substrate and a rigid structure suspended above the substrate to form a backside cavity. Formed in the rigid structure is a reflective diffraction grating positioned to reflect a first portion of an incident light and transmit a second portion of the incident light such that the second portion of the incident light is diffracted. The device also includes a membrane positioned a distance d above the reflective diffraction grating and at least a first photo-detector for receiving interference patterns produced from the first portion of the incident light reflected from the diffraction grating and the second portion of the incident light reflected from the membrane.