Nanosecond wavelength switching of a 16-channel DFB laser array based on REC technology

In this paper, we propose and experimentally verify a 16-channel DFB laser array (DFB-LA) chip, and systematically verify the wavelength switching effect. The DFB-LA chip has a 100 GHz wavelength spacing and is designed as a 4 × 4 matrix. The wavelength spacing of the four series lasers is 400 GHz to reduce the wavelength crosstalk. The experimental results show that the side mode suppression ratio (SMSR) of each wavelength of the proposed DFB-LA is more than 40 dB, and the absolute wavelength deviation is within ± 0.16 nm. A semiconductor optical amplifier (SOA) is monolithically integrated into the chip to enhance the output power. When the current injected into the SOA is 150 mA, the output power of each channel exceeds 45 mW. In order to verify the effect of fast wavelength switching, we designed the corresponding high-speed drive circuit. The rise time of 16 channels is less than 5 ns, and the fall time is less than 7 ns. The optical signal during the switching process is modulated by an external MZ modulator, and a clear optical eye diagram and a bit error rate performance of less than 1 × 10^-10 are obtained under 12.5 Gb/s NRZ data.