Multisection DFB Tunable Laser Based on REC Technique and Tuning by Injection Current

Based on the reconstruction-equivalent-chirp technique and tuning only by the injection current, a multisection DFB tunable laser is demonstrated experimentally. At the temperature of 20°C, each laser can be tuned at about 3.4-3.6 nm with a side-mode suppressing ratio (SMSR) of over 35 dB from 30 to 170 mA, and the tuning speed is about 10-30 ms, which is much faster than that by the thermoelectric cooler. The results may help to realize very low cost tunable lasers in the future.