Abstract

Range, Doppler, and vibration measurements are used in a variety of applications, both military and civilian. The rapid laser development has brought about an increasing diversity in technology. Eye safety, low observability, and cost have been driving forces. A preferred wavelength is 1.54 μm, a wavelength that can be obtained by several types of lasers, one of which is the semiconductor laser. Semiconductor technology can lead to small, robust, and reasonably priced systems. The technology is compatible with fiber optics, which brings about the possibility to use a distributed sensor system. A special case already being exploited is in the area of time domain reflectometry. Due to the limited peak power capability of semiconductor lasers, direct detecting systems based on this technology have been background limited and only reached a limited capability. By using coherent detection and frequency modulation, close to quantum limited systems can be achieved. Similar capability might be obtained in a direct detecting system but only by making use of very advanced filter techniques. The linewidth of DFB and DBR lasers is now narrow enough for many applications. The advancement of semiconductor laser technology has motivated us to develop a compact and versatile coherent FMCW semiconductor laser radar.

© 1994 IEEE