US 8,946,637 B2 · Compact fiber-based scanning laser detection and ranging system

Abstract

A system for short-range laser detection and ranging of targets can provides rapid three-dimensional, e.g., angle, angle, range, scans over a wide field-of-view. Except for the final transmit/receive lens, the disclosed LADAR system can be implemented in an all-fiber configuration. Such system is compact, low cost, robust to misalignment, and lends itself to eye-safe operation by making use of available pulsed 1550 nm fiber lasers and amplifier sources. The disclosed LADAR system incorporates many novel features that provide significant advantages compared to current LADAR systems. The disclosed system uses a monostatic fiber-based transmitter/receiver, a fiber beam scanner based on a laterally vibrating fiber, and a position sensor to monitor the transmitted beam position.

Claims18

Dependent claims

A laser detection and ranging system comprising:

a fiber-based monostatic transmitter/receiver output coupled to a single fiber having an inner core to guide an optical beam for transmission in one direction and an outer core to guide received optical pulses in an opposite direction;
a fiber beam scanner having the single fiber at one end for coupling to the fiber-based monostatic transmitter/receiver output and a fiber tip for transmission at another end, wherein scanning is based on a laterally vibrating fiber cantilever actuated for resonant motion of the optical beam transmitted through the fiber tip;
a transmit/receive lens to collimate said transmitted optical beam as a transmitted collimated optical beam in one direction and receive optical pulses in an opposite direction as said received optical pulses;
and
a position sensor, wherein outputs from said position senor are sampled per pulse to monitor a transmitted beam position and hence propagation angle of the transmitted optical beam.

2 more elements

A monostatic laser detection and ranging system, comprising:

a coupling diplexer output coupled to a proximal end of a single output fiber;
an optical source of transmit light coupled by a source fiber to a source end of said coupling diplexer to transmit light;
a detector/receiver coupled by a receiving fiber to a receiving end of said coupling diplexer to receive light from said proximal end of said single output fiber;
a fiber beam scanner based on a PZT fiber actuator to which a stripped portion of said output fiber is attached, wherein the PZT fiber actuator based fiber beam scanner acts as a cantilever to vibrate a fiber tip, wherein said fiber tip is a distal end of said single output fiber;
a transparent position sensing detector disposed to detect light transmitting from said fiber tip in vibration, wherein outputs from said transparent position sensing detector are sampled per an instant of output to monitor a transmitted beam position;
and
a collimating transmit/receive lens disposed to collimate light transmitted from said fiber tip in vibration through said transparent position sensing detector, wherein, a small 5-20 μm diameter inner core of said single output fiber is used to guide transmit light out through said fiber tip to the transmit/receive lens, and wherein a larger 90-100 μm diameter outer core of said output fiber guides the received light collected by the transmit/receive lens to said fiber tip.

4 more elements

Dependencies are inferred from the claim text.

Compact fiber-based scanning laser detection and ranging system

Life of this patent

Compact fiber-based scanning laser detection and ranging system

Life of this patent

Abstract

Claims18