Honeywell International Inc.

Steven P Ecklund

Timothy J Callaghan

Alan Bruce Touchberry

Thomas A Savard

Lisa P Koland

Daniel R Fashant

Tracy L Sellin

Matthew Clark

Stephen Matthew Baker

Craig A Galbrecht

Mark J Jarrett

Mark Edward Petersen

Gordon Allen Seppanen

Systems and methods for dynamic PLC modulation are provided. In certain embodiments, a gyroscope system includes a block having cavities and passages that define a path; mirrors, each located in one of the cavities, direct light along the path defined by the cavities and the passages; a mirror drive coupled to one of the mirrors to change a position of the mirror, wherein the path's length is changed as the mirror's position changes; a photodetector that measures power of light along the path; and a controller that provides a control signal indicative of an amplitude of PLC modulation and a PLC frequency to the mirror drive; wherein the mirror drive, in response to the control signal, changes the position of the mirror at the frequency, wherein the mirror drive moves based on the amplitude; and wherein the controller changes the amplitude in relation to the measured power of the light.

Systems and methods for dynamic path length control modulation

A ring laser gyroscope configured to reduce alignment shifts in at least one critical alignment of the ring laser gyroscope is provided. The ring laser gyroscope includes reflective components configured to direct clockwise optical beams and counter-clockwise optical beams in at least one lasing plane; at least one ring-laser-gyro mounting feature having at least one respective through hole; and at least one minimally-threaded screw positioned in the at least one respective through hole. An unthreaded section of the minimally-threaded screw is contactlessly encased in the at least one respective through hole. A threaded-end of the at least one minimally-threaded screw is threaded in a respective at least one threaded hole in a gyro frame, the gyro frame spanning a reference mounting plane.

Minimally-threaded screw to reduce alignment shifts

A gyroscope system comprises a gyroscope block having a plurality of cavities and a plurality of passages that define a path; a plurality of mirrors each located in one of the plurality of cavities; at least one mirror drive coupled to one of the plurality of mirrors and configured to change a position of the respective mirror, wherein the path's length is changed by the change in the position of the respective mirror; a dither system coupled to the gyroscope block and configured to induce an angular rotation of the gyroscope block; and a controller configured to provide a dither signal indicative of a dither frequency to the dither system and a path length control (PLC) signal indicative of a PLC frequency to the at least one mirror drive. The controller is configured to calculate the PLC frequency as a function of the dither frequency.

Variable path length control modulation frequency

A method for determining a surface quality of a substrate sample using a differential interference contrast microscope is described. The microscope includes an eyepiece, an eyepiece focus adjustment, a microscope focus adjustment, a light source, at least one of an aperture or reticule, a camera view, a prism and an eyepiece. The method includes calibrating the focus of the eyepiece with the focus of the camera and determining a peak response ratio for the microscope through adjustment of phase between differential beams of the microscope. The substrate sample is placed under the microscope, illuminated with the light source, and brought into focus with the microscope focus. Phase between differential beams is adjusted, at least one image of the substrate sample is captured and processed to determine a level of surface structure on the substrate sample.

Methods and systems for substrate surface evaluation

A method for reducing oxidation of indium seals within a substantially sealed housing is disclosed. The method includes installing a getter within the housing, the getter including a getter material to reduce oxygen and water vapor levels within the housing, reducing oxygen and water vapor levels within the housing relative to ambient air, substantially sealing the housing, and activating the getter within the housing.

Methods and apparatus for removing gases from enclosures

Current control biasing of a ring laser gyroscope is employed to protect electrode seals. A frame of a ring laser gyroscope has more than one electrode attached to it. An electric field is created between the electrodes during the operation of the gyroscope, which causes ions in the frame to migrate towards a lowest electrical potential. Electrode seals are located between the electrodes and the frame. By providing a positive power supply voltage and connecting the current control to the non-ground side of the power supply, the mounting structure may be at the lowest electrical potential. The ions will then migrate towards the mounting structure, which significantly reduces migration to the electrodes.

Current control biasing to protect electrode seals

A ring laser gyro having a high temperature seal. The ring laser gyro includes a laser block of known construction having a closed loop passage formed within the block in the shape of a polygon. Mirrors positioned at the intersection of each side of the polygon-shaped closed loop passage create an optical closed loop path through passage. A lasing gas is sealed within the closed loop passage, and electrodes mounted to the block and in fluid communication with the passage create at least one laser that traverses the optical closed loop path in the passage. The electrodes are mounted on the laser block with a high temperature seal comprising a washer having a low coefficient of thermal expansion and an optical bond between the washer and the laser block In a preferred embodiment, the laser block and the washer are formed from the same material to ensure that these structures expand at substantially the same rate when the ring laser gyro is used in a high temperature application.

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St. Anthony, MN, United States of America

Steven P Ecklund