Passively mode-locked III-V/silicon laser with continuous-wave optical injection.

Yuanbing Cheng,Xiaohui Li,Peng Huei Lim,Guo-Qiang Lo,Tsung-Yang Liow,Qi Jie Wang,Junfeng Song,Yulian Cao,Xianshu Luo,Xiaonan Hu

doi:10.1364/oe.23.006392

Abstract

We demonstrate electrically pumped two-section mode locked quantum well lasers emitting at the L-band of telecommunication wavelength on silicon utilizing die to wafer bonding techniques. The mode locked lasers generate pulses at a repetition frequency of 30 GHz with signal to noise ratio above 30 dB and 1 mW average output power per facet. Optical injection-locking scheme was used to improve the noise properties of the pulse trains of passively mode-locked laser. The phases of the mode-locked frequency comb are shown to be coherent with that of the master continuous-wave (CW) laser. The radio-frequency (RF)-line-width is reduced from 7.6 MHz to 150 kHz under CW optical injection. The corresponding pulse-to-pulse jitter and integrated RMS jitter are 29.7 fs/cycle and 1.0 ps, respectively. The experimental results demonstrate that optical injection can reduce the noise properties of the passively mode locked III-V/Si laser in terms of frequency linewidth and timing jitter, which makes the devices attractive for photonic analog-to-digital converters and clock generation and recovery.

Highlights

Silicon photonics is attracting a lot of attention due to the prospect of integration of compact and cost-effective photonic and microelectronic elements on a single chip [1,2,3]
We demonstrate electrically pumped two-section mode locked quantum well lasers emitting at the L-band of telecommunication wavelength on silicon utilizing die to wafer bonding techniques
The proposed method has been demonstrated as a simple and effective technique to achieve low noise passively III-V/Si mode locked lasers (MLLs) without using high-speed electronics

Summary

Introduction

Silicon photonics is attracting a lot of attention due to the prospect of integration of compact and cost-effective photonic and microelectronic elements on a single chip [1,2,3]. Important achievements have been made in the past on the heterogeneous integration of III–V on silicon using a molecular, metal or adhesive bonding approach [14,15,16].For the mode locked lasers, MLLs with two-section and racetrack structure, have been reported, respectively [17,18,19].Ion implantation was used to realize the confinement of current injection into the device, which greatly complicated the fabrication processes. We describe the realization of a two-section passively MLL on silicon with continuous wave optical injection-locking scheme without using high-speed electronics to improve the noise properties of the pulse trains of passively MLL. The proposed method has been demonstrated as a simple and effective technique to achieve MLLs without using high-speed electronics

Device structure and fabrication

Experimental results and discussions

Conclusion