patents

Aspects of the disclosure relate to an Integrated spectral unit including a micro- electro-mechanical systems (MEMS) interferometer fabricated within a first substrate arid a light redirecting structure- integrated on a second substrate, where the second substrate is coupled to the first substrate. The light redirecting structure includes at least one mirror for receiving an input light beam propagating in an out-of-plane direction with, respect to the first substrate and redirecting the input light beam to an in-plane direction with respect to the first substrate towards the MEMS interferometer.

Aspects relate to an integrated and compact attenuated total internal reflection (ATR) spectral sensing device. The spectral sensing device includes a substrate, a spectrometer, and a detector. The substrate includes an ATR element, a microfluidic channel, and a channel interface at a boundary between the ATR element and the microfluidic channel formed therein. The ATR element is configured to receive input light and to direct the input light to the channel interface for total internal reflection of the input light at the channel interface. An evanescent wave produced by a sample contained within the microfluidic channel based on the total internal reflection of the input light attenuates the light output from the ATR element and the resulting output light may be analyzed using the spectrometer and the detector.

Aspects relate to a compact material analyzer including a light source, a detector, and a module including a first optical window on a first side of the module, a second optical window on a second side of the module opposite the first side, and a light modulator. The light source produces input light at a high power that is passed through the first optical window to the light modulator. The light modulator is configured to attenuate the input light, produce modulated light based on the input light, and direct the modulated light through the second optical window to the sample. The modulated light produced by the light modulator is at a lower power safe for the sample. The detector is configured to receive output light from the sample produced from interaction with the modulated light through the second optical window and to detect a spectrum of the output light.

Aspects relate to a compact material analyzer including a light source, a detector, and a module including a first optical window on a first side of the module, a second optical window on a second side of the module opposite the first side, and a light modulator. The light source produces input light at a high power that is passed through the first optical window to the light modulator. The light modulator is configured to attenuate the input light, produce modulated light based on the input light, and direct the modulated light through the second optical window to the sample. The modulated light produced by the light modulator is at a lower power safe for the sample. The detector is configured to receive output light from the sample produced from interaction with the modulated light through the second optical window and to detect a spectrum of the output light.

Aspects of the present disclosure relate to a self-referencing spectrometer for providing simultaneous measurement of background or reference spectral density and sample or other spectral density. The self-referencing spectrometer includes an interferometer optically coupled to receive an input beam and to direct the input beam along a first optical path to produce a first interference beam and to direct the input beam along a second optical path to produce a second interference beam, wherein each interference beam is produced prior to an output of the interferometer. The spectrometer also includes a detector optically coupled to simultaneously detect a first interference signal generated from the first interference beam and a second interference signal generated from the second interference beam, and a processor configured to process the first interference signal and the second interference signal and to use the second interference signal as a reference signal when processing the first interference signal.

The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later. Various aspects of the disclosure relate to miniaturized gas cells fabricated using semiconductor technology. The miniaturized gas cell may be a multi-pass gas cell or a hollow waveguide gas cell. In some aspects, the miniaturized gas cell may include a bottom surface and sidewalls formed in a substrate (e.g., a silicon substrate or silicon on insulator (SOI) substrate). In some examples, the bottom surface and/or sidewalls may be coated with a reflective material, such as a metal or dielectric coated metal. In other examples, the bottom surface and/or sidewalls may include silicon Bragg mirrors. The gas cell further includes at least one gas inlet and at least one gas outlet coupled for injection of a fluid, such as a gas, liquid, or plasma, into and out of the gas cell, respectively. In addition, the gas cell further includes an optical input and an optical output, each optically coupled to direct light into and out of the gas cell, respectively. The light may be guided in the gas cell by at least the bottom surface and the sidewalls.

Various aspects of the present disclosure provide a micro-optical bench device fabricated by a process that provides control over one or more properties of the micro-optical bench device and/or one or more properties of optical surfaces in the micro-optical bench device. The process includes etching a substrate to form a permanent structure including optical elements and a temporary structure. The shape of the temporary structure and gaps between the temporary structure and the permanent structure facilitate control of a property of the micro-optical bench and/or optical surfaces of optical elements therein. The property may include, for example, surface roughness, selective coating of surfaces, or inclination angles of the surfaces with respect to a plane of the substrate. The process further includes removing the temporary structure from an optical path of the micro-optical bench device. The present invention is directed to a method for fabricating a micro-optical bench device according to claim 1, and subsidiary aspect of the invention are provided in the dependent claims.

The invention is directed to a multi-pass gas cell, which is defined by the appended claims. Embodiments and examples in the following description which are considered not covered by the appended claims are not part of the present invention and are only provided for the purpose of understanding. The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later. The invention is defined by the appended claims. The invention provides a multi-pass gas cell according to claim 1. In some examples, the input and output optical components may include curved mirrors or lenses. In some examples, the set of two or more reflectors may include spherical mirrors, concave mirrors, flat mirrors, or cylindrical mirrors.

Various aspects of the present disclosure provide a spectrometer with increased optical throughput and spectral resolution. Various spectrometers are defined in the claims. The spectrometers include a plurality of scanning interferometers synchronized with each other and coupled in parallel and an optical splitter configured to divide a source light beam into a plurality of input beams and to direct each of the input beams to a respective one of the plurality of interferometers. One or more detectors are optically coupled to receive a respective output from each of the plurality of interferometers and is configured to detect an interferogram produced as a result of the outputs

A shadow mask having two or more levels of openings enables selective step coverage of micro-fabricated structures within a micro-optical bench device. The shadow mask includes a first opening within a top surface of the shadow mask and a second opening within the bottom surface of the shadow mask. The second opening is aligned with the first opening and has a second width less than a first width of the first opening. An overlap between the first opening and the second opening forms a hole within the shadow mask through which selective coating of micro-fabricated structures within the micro-optical bench device may occur.

Aspects relate to mechanisms for increasing the field of view of a spectrometer. An optical device may be configured to simultaneously couple light from different locations (spots) on a sample to the spectrometer to effectively increase the spectrometer field of view. The optical device can include a beam combiner and at least one reflector to reflect light beams from respective spots on the sample towards the beam combiner. The beam combiner can combine the received light beams from the different spots to produce a combined light beam that may be input to the spectrometer.

The present invention relates generally to metallization or thin film coating of optical surfaces in micro-optical bench devices, and in particular, shadow masks that provide selective step coverage of optical surfaces in microfabricated structures within micro-optical bench devices. Regarding manufacturing. Generally, to produce micro-optical components and MEMS components that can process a free space light beam propagating parallel to a silicon-on-insulator (SOI) substrate, on a silicon-on-insulator (SOI) wafer. Deep Reactive Ion Etching (DRIE) process is used to form deeply etched micro-optical benches. Traditionally, one-level shadow masks have been used to provide step coverage of optical surfaces in deeply etched micro-optical benches and selective metallization or thin film coating.

Aspects of the present disclosure relate to an integrated spectroscopy cell comprising a micro-electromechanical system (MEMS) interferometer fabricated within a first substrate and a light redirecting structure integrated on a second substrate, wherein the second substrate is coupled to the first substrate. The light redirecting structure includes at least one mirror for receiving an input light beam propagating in an out-of-plane direction relative to the first substrate and redirecting the input light beam to an in-plane direction relative to the first substrate toward the MEMS interferometer.

The present invention is directed to a Micro Electro-Mechanical System (MEMS) interferometer as defined in claim 1, that uses balancing interfaces to overcome the verticality and dispersion problems. The MEMS interferometer includes a beam splitter formed on a first surface of a first medium at an interface between the first medium and a second medium, a first mirror formed on a second surface of the first medium, a second mirror formed on a third surface of the first medium and the balancing interfaces.

This application claims priority and interests in provisional application Nos. 62 / 350,486 filed with the United States Patent and Trademark Office on June 15, 2016. The entire contents are incorporated herein by reference as if they were fully described below for all applicable purposes. The techniques described below relate to integrated interferometric devices for interference measurement and spectral analysis, especially to integrated microelectromechanical system (MEMS) based interferometric devices.

Aspects of the disclosure relate to a self-referenced spectrometer for providing simultaneous measurement of a background or reference spectral density and a sample or other spectral density. The self-referenced spectrometer includes an interferometer optically coupled to receive an input beam and to direct the input beam along a first optical path to produce a first interfering beam and a second optical path to produce a second interfering beam, where each interfering beam is produced prior to an output of the interferometer. The spectrometer further includes a detector optically coupled to simultaneously detect a first interference signal produced from the first interfering beam and a second interference signal produced from the second interfering beam, and a processor configured to process the first interference signal and the second interference signal and to utilize the second interference signal as a reference signal in processing the first interference signal.

Aspects of the disclosure relate to a multi-pass gas cell that includes a set of two or more reflectors, an input collimating optical component, and an output focusing optical component. The input and output optical components are integrated with at least one of the two or more reflectors. For example, the input and output optical components may be integrated on opposite ends of a single one of the reflectors or may be integrated on the same end of a single reflector. The input and output optical components may further be integrated with different reflectors. In some examples, the set of reflectors and optical components may be fabricated within the same substrate.

Embodiments of the present disclosure provide a Micro-Electro-Mechanical System (MEMS) apparatus for performing self-calibration of mirror positioning. The MEMS apparatus includes at least one mirror having a non-planar surface and a MEMS actuator having a variable capacitance that is coupled to a moveable mirror to cause a displacement thereof. The MEMS apparatus further includes a memory maintaining a table mapping stored capacitances of the MEMS actuator to respective stored positions of the moveable mirror and a capacitive sensing circuit coupled to the MEMS actuator for sensing the capacitance of the MEMS actuator at multiple reference positions of the moveable mirror corresponding to a center burst and one or more secondary bursts of an interferogram produced by the interferometer based on the non-planar surface. A calibration module uses the actuator capacitances at the reference positions to determine a correction amount to be applied to the stored capacitances. The invention is defined by the appended claims.

Aspects of the present disclosure relate to an integrated optical probe card and system for performing wafer testing of optical micro-electro-mechanical systems (MEMS) structures having in-plane optical axes. On-wafer optical masking of optical MEMS structures may be performed with one or more micro-optical platform assemblies to redirect light between an out-of-plane direction perpendicular to an in-plane optical axis and an in-plane direction parallel to the in-plane optical axis to enable testing of the optical MEMS structures by vertical injection of light.

Microelectromechanical Systems (MEMS) devices provide self-calibration of mirror positioning of a movable mirror of an interferometer. At least one mirror in the MEMS device includes a non-planar surface. The moveable mirror is coupled to a MEMS actuator having a variable capacitance. The MEMS device includes a capacitive sensing circuit for determining a capacitance of the MEMS actuator at a plurality of reference positions of the movable mirror corresponding to a central burst and one or more secondary bursts of interferograms generated by the interferometer based on the non-flat surface. The calibration module uses the actuator capacitance at the reference position to compensate for any drift in the capacitive sensing circuit.

Aspects relate to an integrated optical probe card and a system for performing wafer testing of optical micro-electro-mechanical systems (MEMS) structures with an in-plane optical axis. On-wafer optical screening of optical MEMS structures may be performed utilizing one or more micro-optical bench components to redirect light between an out-of-plane direction that is perpendicular to the in-plane optical axis to an in-plane direction that is parallel to the in-plane optical axis to enable testing of the optical MEMS structures with vertical injection of the light.

The shadow mask of opening with two or more levels realizes the selective stepcoverage of the micro Process structure in microoptics bench equipment.Shadow mask is included in the first opening in the top surface of shadow mask and the second opening in the bottom surface of shadow mask.Second opening is aligned with the first opening and with the second width of the first width for being less than the first opening.Overlap between first opening and the second opening forms hole in shadow mask, the Selective coating that the micro Process structure in microoptics bench equipment can occur by the hole.

Embodiments of the present invention provide an optical system including a substrate having a micro-optical bench etched therein using a lithographic and deep etching technique. The optical system further includes an apertured optical element that is monolithically integrated with the micro-optical bench and formed using the lithographic and deep etching technique. The optical element is optically coupled to receive an incident beam having an optical axis in a plane of the substrate and to at least partially transmit the incident beam therethrough via the aperture. In one embodiment, the aperture has a rectangular shape, a trapezoidal shape, a triangular shape, a rounded shape or an arbitrary shape determined by the lithographic and deep etching technique. In a further embodiment, the optical element includes at least two apertures that are homogenous with respect to at least one of a height of each of the at least two apertures, width of each of the at least two apertures and separation between the at least two apertures. At least one side of the optical element is metallized, the optical element may include at least two layers of dielectric material such that the aperture passes through each of the layers, the optical element may include a photonic crystal mirror and/or the optical element may be curved in two dimensions or three dimensions. In another embodiment, the optical element has a reflectivity. The reflectivity may be determined at least in part by one or more of a width of the aperture, an amount of offset between a center of the aperture and the optical axis of the incident beam and a number of apertures within the optical element.

Embodiments of the present invention provide a Micro-Electro-Mechanical System (MEMS) apparatus for performing self-calibration of mirror positioning. The MEMS apparatus includes a movable mirror and a MEMS actuator having a variable capacitance that is coupled to the moveable mirror to cause a displacement thereof. The MEMS apparatus further includes a memory maintaining a table mapping capacitance of the MEMS actuator to position of the moveable mirror, a capacitive sensing circuit coupled to the MEMS actuator for sensing a current capacitance of the MEMS actuator, a digital signal processor for accessing the table to determine a current position of the moveable mirror based on the current capacitance of the MEMS actuator and a calibration module for determining respective actual capacitances of the MEMS actuator at two or more known positions of the moveable mirror to determine a correction amount to be applied to the current position of the moveable mirror. The digital signal processor further produces a corrected current position of the moveable mirror using the correction amount. A MEMS apparatus and MEMS interferometer system of the present invention is as defined by the appended claims.

Microelectromechanical systems (MEMS) refers to the integration of mechanical elements, sensors, actuators, and electrons on a common silicon substrate by microfabrication technology. For example, microelectronics are typically manufactured using integrated circuit (IC) processes, while micro-mechanical components are selectively etched away from portions of silicon wafers or interconnected to add new structural layers. Manufactured using certain microfabrication processes to form mechanical and electromechanical components. Due to their low cost, batch processing capability, and compatibility with standard microelectronics, MEMS devices provide spectroscopy, profilometry, environmental sensing, refractometry (or texture perception), and some other It is an attractive candidate for use in sensor applications. Also, the small size of MEMS devices facilitates incorporating such MEMS devices into mobile and handheld devices.

A shadow mask having two or more levels of openings enables selective step coverage of micro-fabricated structures within a micro-optical bench device. The shadow mask includes a first opening within a top surface of the shadow mask and a second opening within the bottom surface of the shadow mask. The second opening is aligned with the first opening and has a second width less than a first width of the first opening. An overlap between the first opening and the second opening forms a hole within the shadow mask through which selective coating of micro-fabricated structures within the micro-optical bench device may occur.

A kind of MEMS (MEMS) interferometer provides the self calibration of the speculum positioning of movable mirror.Movable mirror is coupled to the MEMS actuator with variable capacitance.MEMS interferometers are included for determining in the capacitance sensing circuit of the capacitance of the MEMS actuator of two or more known positions of movable mirror and for the actuator capacitance in known position to be used to carry out the calibration module of any drift in compensating electric capacity sensing circuit.

A micro-optical bench device is fabricated by a process that provides control over one or more properties of the micro-optical bench device and/or one or more properties of optical surfaces in the micro-optical bench device. The process includes etching a substrate to form a permanent structure including optical elements and a temporary structure. The shape of the temporary structure and gaps between the temporary structure and permanent structure facilitate control of a property of the micro-optical bench and/or optical surfaces therein. The process further includes removing the temporary structure from an optical path of the micro-optical bench device.

Aspects of the disclosure relate to an integrated spectral unit including a micro-electro-mechanical systems (MEMS) interferometer fabricated within a first substrate and a light redirecting structure integrated on a second substrate, where the second substrate is coupled to the first substrate. The light redirecting structure includes at least one mirror for receiving an input light beam propagating in an out-of-plane direction with respect to the first substrate and redirecting the input light beam to an in-plane direction with respect to the first substrate towards the MEMS interferometer.

The present invention relates generally to optical spectroscopy and optical interferometry, and more particularly to the use of micro electro-mechanical system (MEMS) technology in optical interferometers. A micro electro mechanical system (MEMS) refers to a device in which mechanical elements, sensors, actuators, and electronics are integrated on a common silicon substrate by micro processing technology. For example, microelectronics are typically fabricated using an integrated circuit (IC) process, while a compatible microfabrication process is used to selectively etch away portions of a silicon wafer or create new structures. Layers are added to form mechanical and electromechanical components to create micromechanical components. MEMS devices can be batch processed at low cost and are compatible with standard microelectronic devices, so spectroscopy, shape measurement, environmental sensing, refractive index measurement (or material recognition) , And various other sensor applications. In addition, since the MEMS device is small in size, it can be easily integrated into a portable device or a handheld device.

A spectrometer with improved resolution, having a spectral domain modulator with a periodic response in the spectral domain, the spectral domain modulator modulating a broadband light source spectrum and one in the interference waveform. Or it produces multiple shifted bursts.

A kind of optical micro electro-mechanical systems (MEMS) interferometer based on space beam splitting includes the spatial beam separator for inputs light beam space to be beamed into two interferometer beams and the space bundling device for two interferometer beam spaces to be closed to beam.A kind of MEMS moveable mirrors are provided, for generating the optical path difference between the first interferometer beam and the second interferometer beam.

Micromechanical system (MEMS) interferometer systems utilize a capacitive sensing circuit to determine the position of the movable mirror. An electrostatic MEMS actuator is coupled to the movable mirror to cause displacement of the movable mirror. The capacitance detection circuit detects the current capacitance of the MEMS actuator and determines the position of the movable mirror based on the current capacitance of the MEMS actuator.

A spectrometer with increased optical throughput and/or spectral resolution includes a plurality of interferometers coupled in parallel. An optical splitter divides a source light beam into a plurality of input beams and directs each of the input beams to a respective one of the plurality of interferometers. One or more detectors are optically coupled to receive a respective output from each of the plurality of interferometers and is configured to detect an interferogram produced as a result of the outputs.

An optical radiation source produced from a disordered semiconductor material, such as black silicon, is provided. The optical radiation source includes a semiconductor substrate, a disordered semiconductor structure etched in the semiconductor substrate and a heating element disposed proximal to the disordered semiconductor structure and configured to heat the disordered semiconductor structure to a temperature at which the disordered semiconductor structure emits thermal infrared radiation.

A Micro-Electro-Mechanical System (MEMS) interferometer provides for self-calibration of mirror positioning of a moveable mirror. The moveable mirror is coupled to a MEMS actuator having a variable capacitance. The MEMS interferometer includes a capacitive sensing circuit for determining the capacitance of the MEMS actuator at two or more known positions of the moveable mirror and a calibration module for using the actuator capacitances at the known positions to compensate for any drift in the capacitive sensing circuit.

A Micro-Electro-Mechanical System (MEMS) apparatus provides for self-calibration of mirror positioning of a moveable mirror of an interferometer. At least one mirror in the MEMS apparatus includes a non-planar surface. The moveable mirror is coupled to a MEMS actuator having a variable capacitance. The MEMS apparatus includes a capacitive sensing circuit for determining the capacitance of the MEMS actuator at multiple reference positions of the moveable mirror corresponding to a center burst and one or more secondary bursts of an interferogram produced by the interferometer based on the non-planar surface. A calibration module uses the actuator capacitances at the reference positions to compensate for any drift in the capacitive sensing circuit.

A ring laser gyroscope (RLG) includes moveable mirrors and a Micro-Electro-Mechanical Systems (MEMS) actuator coupled to the moveable mirrors to cause a respective displacement thereof that induces a phase modulation on counter-propagating light beams relative to one another. The induced phase modulation creates an optical path difference between the counter-propagating light beams corresponding to a virtual rotation that reduces the lock-in of the RLG.

An integrated apertured micromirror is provided in which the micromirror is monolithically integrated with a micro-optical bench fabricated on a substrate using a lithographic and deep etching technique. The micromirror has an aperture therein and is oriented such that the micromirror is optically coupled to receive an incident beam having an optical axis in a plane of the substrate and to at least partially transmit the incident beam therethrough via the aperture.

The present invention relates generally to optical bench systems, and more particularly to the fabrication of monolithic optical bench systems microfabricated on a substrate.

Embodiments of the present invention provide optical Micro Electro-Mechanical Systems (MEMS) interferometer including a spatial splitter, spatial combiner, moveable mirror and MEMS actuator. The spatial splitter receives an input beam and spatially splits the input beam into first and second interferometer beams. The spatial combiner receives the first and second interferometer beams and spatially combines them to produce an output. Each of the input beam, the first and second interferometer beams and the output beam propagate within a propagation medium that is different from the spatial splitter medium and the spatial combiner medium. The moveable mirror receives one of the first and second interferometer beams and reflects the received beam towards the spatial combiner. The MEMS actuator is coupled to the moveable mirror to cause a displacement thereof to produce an optical path difference between the first interferometer beam and the second interferometer beam. The spatial splitter may include, for example, a truncating splitter, a hollow Multi-Mode interference (MMI) waveguide, a slotted splitter or a Y-splitter. The spatial combiner may include, for example, a focusing element, a hollow MMI waveguide, a slotted combiner, a double slit combiner or a Y-combiner.

An optical rotation sensor includes a Fabry Perot laser having an active gain medium for generating first and second light beams, a closed optical path through which the first and second light beams counter-propagate and first and second mirrors coupled to respective ends of the closed optical path. The first minor is a ring mirror having a complex valued reflectivity that varies with a rotation rate of a frame within which the optical rotation sensor is placed. A detector is coupled to an output of the Fabry Perot laser to measure an output intensity thereof.

A spectrometer with improved resolution includes a spectral domain modulator having a periodic response in the spectral domain to modulate a wideband source spectrum and cause one or more shifted bursts in the interferogram.

A kind of MEMS (micro electro mechanical system) (MEMS) interferometer system uses the position of capacitance sensing circuit determination moveable mirror.Electrostatic MEMS actuator to moveable mirror to cause its displacement.Capacitance sensing circuit senses the capacitance present of MEMS actuator and the position of the capacitance present determination moveable mirror based on MEMS actuator.

This invention relates generally to spectroscopy and interferometry, and more particularly to the use of Micro Electro-Mechanical Systems (MEMS) in optical spectrometers. Micro-electromechanical system (MEMS) refers to the integration of mechanical elements, sensors, actuators and electronics provided on a common silicon substrate, typically by microfabrication techniques. For example, microelectronics are typically manufactured using integrated circuit (IC) processes, and micromechanical components are mechanically and mechanically added by selectively etching away portions of a silicon wafer and adding new structural layers. Manufactured using a microfabrication process that forms electromechanical components. MEMS devices offer spectroscopy, profilometry (shape measurement), environmental sensing, refractive index measurement (material recognition) and other sensors due to their low cost, batch processability, and compatibility with standard microelectronics. An attractive candidate for use in the field. Furthermore, because the MEMS devices are small in size, they can be easily integrated into mobile (mobile) devices and handheld devices.

Optical systems with aspherical optical elements are described. The aspherical optical elements have surfaces in which the in-plane radius of curvature spatially varies and the in-plane cross section surface profile is characterized in that the multiplication of the cosine of the incidence angle raised to a non-zero exponent by the in-plane radius of curvature varies less than twenty percent between any two points on the in-plane cross section surface profile.

The ring laser gyroscope of the present invention is defined by claim 1. Some related features include an active gain medium for generating first and second light beams, a closed optical path through which the first and second light beams counter-propagate, first and second moveable mirrors within the closed optical path and a Micro-Electro-Mechanical Systems (MEMS) actuator coupled to the first and second moveable mirrors to cause a respective displacement thereof that induces a phase modulation on the first and second light beams relative to .one another, thereby creating an optical path difference between the first and second light beams corresponding to a virtual rotation to reduce the lock-in.

An optical system, such as an integrated monolithic optical bench, includes a three-dimensional curved optical element etched in a substrate such that the optical axis of the optical system lies within the substrate and is parallel to the plane of the substrate.

The present invention relates generally to micro electro-mechanical systems (MEMS) devices, and more particularly to MEMS actuators. The microelectromechanical system (MEMS) means a device in which mechanical elements, sensors, actuators, and electronics (electronic devices) are integrated on a common silicon substrate by microfabrication technology. For example, microelectronics are typically fabricated using an integrated circuit (IC) process, while micromechanical components use a micromachining process similar to that process to selectively select portions of a silicon wafer. It is produced by forming mechanical parts and electromechanical parts by etching away or adding new structural layers. MEMS devices are low-cost, can be batch-produced, and are compatible with standard microelectronics, so they can be used for spectroscopic measurement, shape measurement, environmental sensing, refractive index measurement (or material recognition), and other sensor applications An attractive candidate suitable for. Furthermore, since the MEMS device is small in size, the MEMS device can be integrated into a mobile device or a handheld device.

The present invention relates generally to optical MEMS, and more particularly to optical scanners using MEMS. Micro Electro-Mechanical System (MEMS) means the integration of mechanical elements, sensors, actuators, and electronics (electronic equipment) on a common silicon substrate by microfabrication technology. To do. For example, microelectronics are typically fabricated using an integrated circuit (IC) process, while micromechanical components use a micromachining process similar to that process to selectively select portions of a silicon wafer. It is produced by forming mechanical parts and electromechanical parts by etching away or adding new structural layers. MEMS devices are low-cost, can be batch-produced, and are compatible with standard microelectronics, so they can be used for spectroscopic measurement, shape measurement, environmental sensing, refractive index measurement (or material recognition), and other sensor applications An attractive candidate suitable for. Furthermore, since the MEMS device is small in size, the MEMS device can be integrated into a mobile device or a handheld device.

A process for preparing alumina comprising leaching an aluminum-containing material with HCl and separating the solid from the leachate to obtain a leachate and solid containing aluminum ions, magnesium ions; MgCl2 Substantially selectively precipitating from the leachate and removing the MgCl2 from the leachate; to obtain a precipitate containing aluminum ions in the form of liquid and AlCl3, the leachate is reacted with HCl and the precipitate Separating the product from the liquid; heating the precipitate under conditions effective to convert AlCl 3 to Al 203; and heating MgCl 2 under conditions effective to convert to MgO; and Recovering gaseous HCl thus produced from heating by heating.

A Micro Electro-Mechanical System (MEMS) spectrometer architecture compensates for verticality and dispersion problems using balancing interfaces. A MEMS spectrometer/interferometer includes a beam splitter formed on a first surface of a first medium at an interface between the first medium and a second medium, a first mirror formed on a second surface of the first medium, a second mirror formed on a third surface of the first medium and balancing interfaces designed to minimize both a difference in tilt angles between the surfaces and a difference in phase errors between beams reflected from the first and second mirrors.

A Micro Electro-Mechanical System (MEMS) interferometer system utilizes a capacitive sensing circuit to determine the position of a moveable mirror. An electrostatic MEMS actuator is coupled to the moveable mirror to cause a displacement thereof. The capacitive sensing circuit senses the current capacitance of the MEMS actuator and determines the position of the moveable mirror based on the current capacitance of the MEMS actuator.

An interferometer includes a variable optical path length reference mirror to produce a final interferogram from a combination of interferograms. Each of the interferograms is generated at a different optical path length of the reference mirror.

An electrostatic comb drive actuator for a MEMS device includes a flexure spring assembly and first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof. Each of the first and second comb assemblies includes fixed comb drive fingers and moveable comb drive fingers coupled to the flexure spring assembly and extending towards the fixed comb drive fingers. The comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly. When electrically energized, the moveable comb drive fingers of both the first and second comb drive assemblies simultaneously move towards the fixed comb drive fingers of the first and second comb drive assemblies.

A Micro Electro-Mechanical System (MEMS) spectrometer architecture compensates for verticality and dispersion problems using balancing interfaces. A MEMS spectrometer/interferometer includes a beam splitter formed on a first surface of a first medium at an interface between the first medium and a second medium, a first mirror formed on a second surface of the first medium, a second mirror formed on a third surface of the first medium and balancing interfaces designed to minimize both a difference in tilt angles between the surfaces and a difference in phase errors between beams reflected from the first and second mirrors.

A Mach-Zehnder MEMS interferometer is achieved using two half plane beam splitters formed at respective edges of a first medium. The first beam splitter is optically coupled to receive an incident beam and operates to split the incident beam into two beams, a first one propagating in the first medium towards the second beam splitter and a second one propagating in a second medium. A moveable mirror in the second medium reflects the second beam back towards the second beam splitter to cause interference of the two beams.

A micromachined interferometer (10) is achieved using a half plane beam splitter. The beam splitter is optically coupled to receive an incident beam (I) and operates to split the incident beam into two interfering beams (L1 and L2), each propagating in a different medium. A fixed mirror (M2) embedded in one of the mediums reflects one of the interfering beams (L2) back towards the half plane beam splitter through such medium, while a moveable mirror (M1), which is controlled by an actuator (40), reflects the other interfering beam (L1) back towards said half plane beam splitter through the other medium. A detection plane (D1 or D2) detects an interference pattern produced as a result of interference between the reflected interfering beams (L3 and L4).

An optical microscanner achieves wide rotation angles utilizing a curved reflector. The optical microscanner includes a moveable mirror for receiving an incident beam and reflecting the incident beam to produce a reflected beam and a Micro Electro-Mechanical System (MEMS) actuator that causes a linear displacement of the moveable mirror. The curved reflector produces an angular rotation of the reflected beam based on the linear displacement of the moveable mirror.

Embodiments of the present invention provide an optical Micro Electro-Mechanical System (MEMS) device providing an optical path retardation multiplier. The MEMS device includes a moveable corner cube reflector, a fixed mirror and a MEMS actuator. The moveable corner cube reflector is optically coupled to receive an incident beam on one edge of the corner cube reflector and operable to reflect the incident beam from another edge of the corner cube reflector. The fixed mirror is optically coupled to receive the incident beam reflected from the moveable corner cube reflector and operable to reflect the incident beam back towards the moveable corner cube reflector as a reflected beam along a reverse path of the incident beam. The MEMS actuator is coupled to the moveable corner cube reflector to cause a displacement of the moveable corner cube reflector perpendicular to a plane of the fixed mirror to extend an optical path length of the reflected beam.

An optical Micro Electro-Mechanical System (MEMS) device provides an optical path retardation multiplier. The MEMS device includes a moveable corner cube reflector, a fixed mirror and a MEMS actuator. The moveable corner cube reflector is optically coupled to receive an incident beam and reflect the incident beam through 180 degrees towards the fixed mirror. The fixed mirror is optically coupled to reflect a reflected beam back towards the moveable corner cube reflector along a reverse path of the incident beam. The MEMS actuator is coupled to the moveable corner cube reflector to cause a displacement of the moveable corner cube reflector to extend an optical path length of the reflected beam.

An electrostatic comb drive actuator for a MEMS device includes a flexure spring assembly and first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof. Each of the first and second comb assemblies includes fixed comb drive fingers and moveable comb drive fingers coupled to the flexure spring assembly and extending towards the fixed comb drive fingers. The comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly. When electrically energized, the moveable comb drive fingers of both the first and second comb drive assemblies simultaneously move towards the fixed comb drive fingers of the first and second comb drive assemblies.

An optical Micro Electro-Mechanical System (MEMS) device provides an optical path retardation multiplier. The MEMS device includes a moveable corner cube reflector, a fixed minor and a MEMS actuator. The moveable corner cube reflector is optically coupled to receive an incident beam and reflect the incident beam through 180 degrees towards the fixed mirror. The fixed minor is optically coupled to reflect a reflected beam back towards the moveable corner cube reflector along a reverse path of the incident beam. The MEMS actuator is coupled to the moveable corner cube reflector to cause a displacement of the moveable corner cube reflector to extend an optical path length of the reflected beam.

A micromachined interferometer is achieved using a half plane beam splitter. The beam splitter is optically coupled to receive an incident beam and operates to split the incident beam into two interfering beams, each propagating in a different medium. A fixed mirror embedded in one of the mediums reflects one of the interfering beams back towards the half plane beam splitter through such medium, while a moveable mirror, which is controlled by an actuator, reflects the other interfering beam back towards said half plane beam splitter through the other medium. A detection plane detects an interference pattern produced as a result of interference between the reflected interfering beams.

A micromachined interferometer (10) is achieved using a half plane beam splitter. The beam splitter is optically coupled to receive an incident beam (I) and operates to split the incident beam into two interfering beams (L1 and L2), each propagating in a different medium. A fixed mirror (M2) embedded in one of the mediums reflects one of the interfering beams (L2) back towards the half plane beam splitter through such medium, while a moveable mirror (M1), which is controlled by an actuator (40), reflects the other interfering beam (L1) back towards said half plane beam splitter through the other medium. A detection plane (D1 or D2) detects an interference pattern produced as a result of interference between the reflected interfering beams (L3 and L4).