Skip to Main Content
Recent advances in laser transmitter technology have made available to the laser radar system designer a multitude of wavebands from which to choose. There are four infrared wavebands receiving emphasis for modest to long range (1-10 km) imaging applications each of which contains efficient, mature source technologies suitable for commercial or tactical military applications. These wavebands include far-IR band centered at 10.6 /spl mu/m and the near-IR band with three subbands located near 2 /spl mu/m, 1.5 /spl mu/m, and 1 /spl mu/m. Visible wavelengths are usually avoided for reasons of eye-safety or detectability. The near-IR subbands coincide with the peak spectral responses of the three most suitable photodetector materials in the near-IR band and include a variety of lasing molecules, ions, transitions, and host materials. The most efficient and mature of these include the CO/sub 2/ gas laser at 10.59 /spl mu/m, the holmium, thulium solid-state laser(s) near 2 /spl mu/m, the optical parametric down converted neodymium solid-state laser(s) operating near 1.5 /spl mu/m, and the neodymium laser(s) operating near 1 /spl mu/m. Diode lasers are not considered due to their low peak power capabilities. A brief comparative performance analysis is presented for the ground-to-ground scenario which discusses the key tradeoff issues between the various wavebands with emphasis on atmospheric effects, including atmospheric turbulence. A nominal set of system requirements and design parameters are chosen which, when used in the analysis, lend insight into the performance trends expected for the various wavebands. Atmospheric propagation is modeled using MODTRAN and FASCOD3 for medium and high resolution spectral absorption profiles, respectively. Example field data is presented from the Raytheon Electronic Systems 10.59 /spl mu/m coherent Tri-Service Laser Radar (TSLR), a Hercules Defense Electronic Systems, Inc. 1.064 /spl mu/m Neodymium direct detection laser radar and a F- bertek, Inc. 1.54 /spl mu/m OPO:Nd direct detection system.