High resolution laser LIDAR utilising two-section distributed feedback semiconductor laser as a coherent source

An air-spaced coherent LIDAR (light detection and ranging) employing a two-section distributed feedback (DFB) injection laser is demonstrated. The relative distance of a mirror target was detected with 0.1 mu m resolution. The absolute distance of a diffuse target was measured with 1 cm accuracy. These results indicate that semiconductor lasers developed for communication systems may be useful for sensing applications such as robotic vision, surface profiling and automated fabrication.