Single-sideband characteristics of photonic microwave signals generated with optically injected quantum-dot and quantum-well semiconductor lasers
Chih-Ying Chen1*, Fan-Yi Lin1
1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:陳質穎,
Generations of single-sideband (SSB) photonic microwave signals with reduced power penalty in fiber transmission have been demonstrated in optically injected quantum-well (QW) semiconductor lasers. While quantum-dot (QD) semiconductor lasers are known for their advantages of lower threshold current, higher temperature stability, and smaller linewidth enhancement factor, the SSB characteristics of photonic microwave signals generated with optically injected QD lasers have however not been investigated.
In this study, we experimentally compare the characteristics of photonic microwave signals, including the microwave frequency, microwave power, and sideband rejection ratio (SRR), generated from QD and QW lasers. Under the condition of optimal microwave power, the QD laser is shown to have a SRR 15 dB higher than the QW laser for microwave frequencies ranging from 6 GHz to 22 GHz. It is found that this larger SRR is attributed to the smaller linewidth enhancement factor and carrier relaxation decay rate in the QD laser. As the results, compared with the QW lasers, the SSB photonic microwave signals generated by optically injected QD lasers are expected to have less power penalty effect and better transmission performance.

Keywords: photonic microwave, quantum-dot laser, quantum-well laser, single-sideband, optical injection