106-Gb/s PAM4 Operation of Directly Modulated DFB Lasers from 25 to 70 °C for Transmission Over 2-km SMF in the CWDM Range

Four newly developed directly modulated DFB lasers operating in the 1.3-μm CWDM wavelength range demonstrated 106-Gb/s PAM4 operation for transmission over 2-km SMF at temperatures of 25, 50 and 70 °C. Eye diagrams of the DMLs were clearly opened after 500-m and 2-km SMF transmission, even at 70 °C, and their TDECQ values were equal or lower than 3.4 dB in BTB configuration up to 50 °C. The results of dispersion penalties in the CWDM range were less than +0.8 dB from 25 to 70 °C. These results indicate that the four developed DMLs can realize a cost-effective transceiver with low power consumption for 400GbE and beyond.