Wavelength-tunable traveling-wave semiconductor ring-laser

Abstract

A traveling-wave ring-laser (10) to provide improved power stability single longitudinal mode characteristics, narrow lasing linewidth and smooth wavelength tuning. The ring-laser comprises an optical amplifier (12) that includes a first facet (16) and a second facet (42). Optical amplifier (12) generates laser light from first facet (16) ring-laser (10) directs a portion of the laser light from first facet (16) back into second facet (42). An Faraday rotator (32) and half-wave plate (30) direct a portion of laser light that second facet (42) receives to travel in one direction only from first facet (16) to second facet (42). By feeding back input from optical amplifier (12) first facet 16 into second facet 42, lasing occurs. Causing laser light from first facet (16) to travel in one direction provides for smooth wavelength tuning and stable power performance single longitudinal mode and narrow-linewidth characteristics in laser system (10). A wavelength selective grating (36) associates with ring-laser system (10) to permit wavelength tuning by mechanical varying grating angle of mechanical grating (36). The traveling-wave ring-laser system (10) has applications in fiber optic communications, high-resolution spectroscopy, optical recording and optical readout second harmonic wavelength conversion processes microwave and millimeter wave generation, and picosecond pulse generation, and fiber sensor application.