Ladar using broadband optical source

Abstract

A simultaneously broadband laser has been developed for laser radar (LADAR) applications. Simultaneous broadband operation is important in enabling rapid (single pulse) data measurement, avoiding atmospheric scintillation or turbulence effects that can dog a more conventional laser which is sequentially tuned to a series of probe wavelengths. The laser is based on an optical parametric oscillator (OPO) operating in a non-collinear critical phase matching geometry, thereby enabling broadband operation. p-Barium Borate (BBO) is pumped by a frequency tripled NdYag laser to achieve lasing from 500-1220nm. The laser is further able to simultaneously lase at an arbitrary series of narrow wavelengths chosen to correspond to the absorption lines of a trace gas. The laser has been demonstrated with an output pulse energy exceeding 4OmJ with an instantaneous full bandwidth greater than l5Onm in the visible. The paper describes the current state of this laser development programme. Laboratory and test trial results are presented.

Development of a broadband lidar system for remote determination of aerosol size distributions

“…A similar device based on BBO and pumped at 355 nm has previously been developed, producing a broadband signal output in the visible (480-650 nm) [11]. This has been used by DERA as a lidar source for field trials [12]. Huang et al [13,14] investigated a broad spectral bandwidth OPO with signal 745-890 nm but did not attempt to re-collimate the idler or measure its slope efficiency.…”