Quantum Dot Fourth-harmonic Colliding Pulse Mode-locked Laser for High Power Optical Comb Generation

Quantum-dot mode-locked lasers have the advantages such as high temperature stability, large optical bandwidth, low power consumption, which makes it an ideal optical comb source, especially for wavelength division multiplexing (WDM) telecommunications and optical I/O applications. In this work, we demonstrated O-band quantum dot colliding pulse mode-locked laser (CPML) to generate optical frequency combs with 200 GHz spacing with maximum channels of 12 within 3 dB optical bandwidth. To achieve high output power of individual comb line, 4 channel conditions are implemented at central wavelength of 1310 nm for WDM transmission experiments. Each channel exhibits more than 10 dBm output power with 200 Gb/s PAM-4 and 270 Gb/s PAM-8 modulation capability via thin film LiNO3 MZI modulator without requirement of any optical amplifications. This high-order QD CPML is an ideal comb source for power-efficient optical interconnects and large bandwidth optical data transmission.