1.55-μm InGaAsP distributed feedback vapor phase transported buried heterostructure lasers

1.55-μm single longitudinal mode InGaAsP distributed feedback (DFB) lasers have been fabricated using a vapor phase transported (VPT) buried heterostructure geometry on a liquid phase epitaxially grown broad area DFB base. Lasing thresholds in the 35-65-mA range were obtained, with side mode suppression ratios as high as 39 dB under modulation. The VPT DFB laser has both a good high-speed modulation capability and low wavelength chirping under high-speed modulation, making it an attractive candidate for high bit rate, long-haul optical fiber systems applications, with demonstrated record system performance at both 2 and 4 Gbit/s.