Improved Sampled Grating DBR Widely-Tunable 1.55 micrometer-Lasers

摘要

Over the last three years, a number of improvements have been made in the design of SGDBR lasers with integrated componentry. Device design has improved the output power and tuning range due to an increase in the number of quantum wells in the active region from four to six. Devices with up to 8 mW of output power with integrated amplifiers and buried heterostructure devices with 72 nm tuning ranges were realized. Current laser results indicate that leakage current in buried heterostructure lasers is a major factor in limiting the device performance. To eliminate the parasitic leakage paths we have begun to investigate Fe doped blocking junctions for the device. Work on the wavelength monitor has focused on an external approach, which uses a wavelength dependent coupler in conjunction with a pair of photodetectors. Initial results show better than 1 nm sensitivity over a 30 nm range. The most recent work on the laser has focused on integrating additional components for increased functionality. We have developed a curved waveguide semiconductor optical amplifier that can be integrated with the laser to increase the output power to greater than 6 mW. We have also investigated SGDBR lasers with integrated electro-absorption modulators. Using a 300 micrometers long bulk EA modulator we have demonstrated error free data transmission at 2.5 GBit/s with a 2 (exp 31) - 1 pattern length at received powers of -32.5 dBm.