Abstract

Laser ranging and other active target-acquisition systems typically transmit and receive the same wavelengths. In these systems the targets are passive and serve only to scatter the incident transmitter signals. This approach, although widely employed, suffers from the drawback of false positives associated with returns from other objects. In this paper we describe a ranging system based on a new type of active target that uses the incident transmitter energy to excite omnidirectional laser action in the target. These co-operative targets are based the recent discovery of laser action in systems composed of laser dyes and scatterer particles in a host.¹ The materials operate efficiently at thicknesses of about 100 µm and can be employed as paints, as polymer sheets or in textile form.

© 1995 Optical Society of America