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