Abstract

Hitherto, the major drawbacks with a semiconductor laser based CLR have been a low power output and a fairly short coherence length. However, with the progress in semiconductor laser development, both these quantities are rapidly increasing and this in turn have made a semiconductor laser based CLR feasible. A CLR of this kind can offer several advantages, some of which are: i) The laser radar can be made physically small which is important in many applications, ii) Along with the smallness follows robustness, i. e. a small system can be less sensitive to external impetus, iii) The cost for a diode-based CLR can be comparatively low. iv) It is possible to achieve eye-safety: the distributed feedback (DFB) laser used in this study operates at the eye-safe wavelength 1.55 μm. v) The laser can be frequency modulated. Therefore, the laser can be run continuously with a relatively low power output and this in turn means low observability, which in some applications is yet another advantage, vi) Compatibility with fibre technology which allows for e. g. distributed measurements.

© 1995 Optical Society of America