Abstract

Successful large-scale introduction of coherent-lidar/remote-sensing techniques in environmental monitoring is hindered currently by the relatively high cost of continuously tunable, narrow-linewidth laser sources, as well as their relative bulkiness that preclude their installations in confined spaces. While semiconductor lasers are currently massed-produced at low cost, the requirements of narrow-linewidth and continuously tunable necessitates coupling the laser diode to an external cavity grating which makes its cost very high. In this paper, we describe a new technology that has evolved in the past year, that uses silicon micromachining technology to implement a miniaturized, lost cost, continuously tunble, highly coherent, micro External- Cavity semiconductor Laser (micro-ECL). The entire optical system is built on a silicon chip measuring less than 0.3cm square, and on-chip micromotors are used to drive the grating reflector for continuous wavelength tuning. The semiconductor laser can also be made to emit very short, wavelength tunable pulses by simply electrically driving the laser diode. A schematic of the micro-ECL is shown in Fig. 1.

© 1995 Optical Society of America