Raytheon Company

Mark K Lange

Gerald P Uyeno

Sean D Keller

Benn H Gleason

Craig O Shott

Eric Rogala

Garret A Odom

Jon E Leigh

Vanessa Reyna

Zachary D Barker

David James Knapp

The design of an existing air-to-air missile seeker is adapted to new missions that require both active laser illumination and detection (passive or active) capabilities. The gimbal is used to point the laser beam to a desired location in a transmit FOR. This approach minimizes the size, weight and power of the sensor because only a small portion of the transmit FOR is illuminated at any instant. This minimizes the laser output required, which reduces the power to operate the laser and the power to maintain the laser at operating temperature. In existing seekers, the gimbal points the detector in the desired direction to expand its FOR. To address the limitations of coupling the laser beam into the gimbaled optical system, the gimbal cannot perform the steering function for the detector. Instead, a staring detector receives light through an off-gimbal aperture within a fixed receive FOR that overlaps the transmit FOR.

Optical sensor with dual-axis gimballed transmitter and staring detector

An optical scanning system includes one or more Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) used to scan a field-of-view (FOV) over a field-of-regard (FOR). The MEMS MMA is configured such that optical radiation from each point in the FOV does not land on or originate from out-of-phase mirror segments and a diffraction limited resolution of the optical system is limited by the size of the entrance pupil and not by the size of individual mirrors.

Optical scanning system using micro-electro-mechanical system (mems) micro-mirror arrays (MMAs)

Optical sensors and particularly gimbaled optical sensors transmit an active signal at a given wavelength and receive passive signals over a range of wavelengths while controlling pointing without benefit of measuring and locating the active signal return. The sensor includes a Tx/Rx Aperture Sharing Element (ASE) is configured to block the received active signal (e.g. reflections off a target in a scene) and process only the passive emissions. These optical sensors may, for example, be used with guided munitions or autonomous vehicles.

Optical sensor with Tx/Rx aperture sharing element (ASE) to block detection of the received active signal

A beam steering architecture for an optical sensor is based upon a pair of Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) and a fold mirror. The MEMS MMAs scan both primary and secondary FOR providing considerable flexibility to scan a scene to provide not only active imaging (to supplement passive imaging) but also simultaneously allowing for other optical functions such as establishing a communications link, providing an optical transmit beam for another detection platform or determining a range to target. A special class of MEMS MMAs that provides a 'piston' capability in which the individual mirrors may translate enables a suite of optical functions to 'shape' the optical transmit beam.

Optical sensor with micro-electro-mechanical system (MEMS) micro-mirror array (MMA) steering of the optical transmit beam

An optical sensor uses a MEMS MMA to scan a narrow laser beam over a transmit FOR to provide active illumination and to correct the beam profile (e.g., collimate the beam, reduce chromatic aberrations, correct the beam profile or wavefront). A staring detector senses light within a receive FOR that at least partially overlaps the transmit FOR. By completely eliminating the dual-axis gimbal, this sensor architecture greatly reduces the volume and weight of the optical sensor while avoiding the deficiencies of known systems associated with either fiber or free-space coupling of the laser beam into an existing receiver.

Optical sensor with MEMS MMA steered transmitter and staring detector

Small angle optical beam steering is performed using a Micro-Electro-Mechanical System (MEMS) Micro-Mirror Array (MMA) that minimizes diffraction for a specified steering angle, Generally speaking, this is accomplished with a MEMS MMA that exhibits a 'piston' capability to translate individual mirrors in addition to the tip and tilt capabilities. Adjacent mirrors can be tipped/tilted to the specified steering angle and then translated by a requisite amount to approximate a continuous surface. For a specified steering angle, the MEMS MMA is partitioned into one or more sections with each section including the maximum number of mirrors that can be grouped together and actuated to approximate a continuous surface given a maximum translation z. As a result, the only edge discontinuities exist between adjacent sections thereby minimizing distortion for a given steering angle.

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Tucson, AZ, United States of America

Mark K Lange