High-speed wavelength-swept semiconductor laser with a polygon-scanner-based wavelength filter

TLDR

The laser employs a unidirectional fiber‑optic ring resonator with a semiconductor optical amplifier and a polygon‑scanner‑based filter. The system achieves ultrahigh‑speed tuning up to 1150 nm/ms (15.7 kHz) over a 70‑nm span at 1.32 µm, more than ten times faster than prior work, with a sub‑0.1 nm linewidth, 9‑mW output, and –80 dB spontaneous‑emission background, aided by self‑frequency shifting in the amplifier.

Abstract

Ultrahigh-speed tuning of an extended-cavity semiconductor laser is demonstrated. The laser resonator comprises a unidirectional fiber-optic ring, a semiconductor optical amplifier as the gain medium, and a novel scanning filter based on a polygonal scanner. Variable tuning rates up to 1150 nm/ms (15.7-kHz repetition frequency) are demonstrated over a 70-nm wavelength span centered at 1.32μm . This tuning rate is more than an order of magnitude faster than previously demonstrated and is facilitated in part by self-frequency shifting in the semiconductor optical amplifier. The instantaneous linewidth of the source is <0.1 nm for 9-mW cw output power and a low spontaneous-emission background of -80 dB .