1.8-THz-wide optical frequency comb emitted from monolithic passively mode-locked semiconductor quantum-well laser

TL;DR

This paper demonstrates a monolithic, passively mode-locked quantum-well laser on a photonic integrated circuit that generates an ultra-wide 1.8 THz optical frequency comb with ultrafast pulses and stable radio frequency beat notes.

Contribution

It introduces a 1.8 THz-wide optical frequency comb from a monolithic quantum-well laser integrated on a photonic chip, using a novel cavity design with intracavity phase modulators.

Findings

Achieved a 14 nm (~1.8 THz) spectral bandwidth optical comb.

Generated ultrafast pulses of 0.35 ps width.

Displayed a stable RF beat note with 450 kHz linewidth.

Abstract

We report on an optical frequency comb with 14nm (~1.8 THz) spectral bandwidth at -3 dB level that is generated using a passively mode-locked quantum-well (QW) laser in photonic integrated circuits (PICs) fabricated through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse mode-locked laser cavity is defined by on-chip reflectors incorporating intracavity phase modulators followed by an extra-cavity SOA as booster amplifier. A 1.8-THz-wide optical comb spectrum is presented with ultrafast pulse that is 0.35-ps-wide. The radio frequency beat note has a 3-dB linewidth of 450 kHz and 35-dB SNR.