Abstract

Single-wavelength semiconductor lasers with wavelength monitoring capability are very important for dense wavelength- division multiplexed (WDM) communication systems. Monolithic integration of distributed feedback (DFB) or distributed Bragg reflector (DBR) laser with wave-guide-type spectrometer could be realized by photonic integrated circuit (PIC). However, the spectrometer occupies a very large area, which results in low yield and high cost. Furthermore, the wavelength matching between the lasers and the spectrometer further complicates the fabrication tolerance. On the other hand, very-low-cost free-space microspectrometers can be mass-produced by the surface-micromachining technique on Si substrate. By combining the DFB laser or the WDM laser array with the microspectrometer on the Si free-space micro-optical bench (FSMOB), low-cost and highperformance WDM source can be obtained. In this paper, we believe we report on the first demonstration of the free-space micro-optical system consisting of a DFB laser and a surface-micro-machined precision wavelength-meter on a Si micro-optical bench.

© 1996 Optical Society of America