Ladar system for detecting objects

US6844924B2 · kind B2 · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• William C. Ruff · Baltimore, US
• Barry L. Stann · Silver Spring, US
• Paul H. Shen · North Potomac, US

Key dates

• Filing date: Jun 28, 2002
• Grant date: Jan 18, 2005
• Expiry date: Jun 28, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S17/894
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A high range resolution ladar includes a chirp generator for producing a chirp signal waveform that is used by a laser diode to propagate a divergent laser light waveform. The reflected light signals from the target are directed to a self mixing detector that is coupled to the chirp generator where the responsivity of the detector varies in accordance with the chirp waveform for converting reflected light signals from the target to electrical signals and for mixing the converted electrical signal with the chirp waveform to produce an output electrical signal whose frequency is proportional to the range to the target. The self-mixing detector includes at least one detector having a semiconductor substrate and first and second electrodes deposited on the substrate and spaced from each other, wherein the first set of electrodes is connected to the chirp generator and the second set of electrodes is connected to a memory for storing a plurality of frames of image data.