High Power Laser Diodes as LADAR Illuminators:Atmospheric Considerations

摘要

Recent advances in low-cost high power diode lasers have made available a new type of illuminator source for LADAR remote sensing systems. These sources tend to be smaller more rugged, and have better power conversion efficiency than more conventional pumped crystal solid state lasers. They can be run in short pulse, or long pulse modes with pulse repetitions from DC to lOs of kilohertz. Although they don't have the peak power of a Q-switched laser, they make up for it in higher average power. They also tend to have large optical band widths. These factors make them well suited to direct detection, as opposed to coherent detection, since the lower source coherence reduces detrimental atmospheric effects related to speckle noise and scintillation of the outgoing beam. In this paper we discuss these effects and situations where diode lasers provide an advantage when working through long slant paths.