Santa Barbara Research Center

Raytheon Company

William O McKeag

Russell D Granneman

James F Asbrock

John E Clement

A method for ranging or targets may include transmitting a pulse of electromagnetic energy at a target. The method may also include generating a time-varying signal in response to receiving a first signal indicating transmission of the pulse of electromagnetic energy. Additionally, the method may include detecting a reflection of the pulse from the target. Moreover, the method may include generating a second signal indicating detection of the reflection. The method may further include generating a third signal substantially equivalent to the second signal delayed by predetermined delay. The method may also include sampling the time-varying signal in response to receiving the third signal.

System and method for ranging of targets

A focal plane array (10) of radiation detectors (10b) has all features inclined with respect to an illuminating beam of radiation. That is, all features that would be orthogonally disposed with respect to an incoming wavefront are instead inclined to the incoming wavefront, an arrangement referred to as compound tipping. The disclosed embodiments of the invention create a compound tipping of the focal plane array such that there are no features of the array, such as mesa edges and sidewalls, that lie in the plane of the incoming wavefront. As a result, only a small amount of scattered light is observed, and the optical signature is significantly reduced. The invention substantially eliminates the optical signature by simultaneously tipping the focal plane features (optically and/or mechanically) in both major array axes, without degrading the imaging performance of the detective assembly.

Compound optically tipped detectors

A radiation detector includes a photovoltaic diode mesa structure (16) having of a plurality of sub-mesa structures (16a, 16b). Each of said sub-mesa structures includes a first layer (14a) of semiconductor material having a first type of electrical conductivity and a second layer (14b) having a second type of electrical conductivity such that a p-n junction is formed between the first and the second layers. Metalization (24) is disposed within a trench (30a) that runs between the sub-mesas and includes a tab portion (24a) that extends upwardly over a sidewall of each of said sub-mesa structures so as to electrically contact the second layer contained within each. As a result, each of said sub-mesa structures are electrically connected in parallel. The trench is disposed parallel to a radiation scan axis of the radiation detector and orthogonal to a radiation cross-scan axis of the radiation detector for reducing a width of surface features across the scan axis, thereby reducing a light signature of the detector.

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Santa Barbara, CA, United States of America

William O McKeag