A narrow-linewidth external cavity quantum dot laser for high-resolution spectroscopy in the near-infrared and yellow spectral ranges

TL;DR

This paper presents a tunable, narrow-linewidth quantum dot laser system suitable for high-resolution spectroscopy in the near-infrared and yellow spectral ranges, with demonstrated frequency stabilization and potential for precision atomic and molecular measurements.

Contribution

It introduces a novel quantum dot laser with tunability, narrow linewidth, and frequency stabilization capabilities for spectroscopy applications.

Findings

Linewidth reduced to 20-30 kHz with stabilization

Laser tunable from 1125 to 1280 nm

Generated yellow light at 578 nm via frequency doubling

Abstract

We demonstrate a diode laser system which is suitable for high-resolution spectroscopy in the 1200 nm and yellow spectral ranges. It is based on a two-facet quantum dot chip in a Littrow-type external cavity configuration. The laser is tunable in the range 1125 -1280 nm, with an output power of more than 200 mW and exhibits a free-running linewidth of 200 kHz. Amplitude and frequency noise were characterized, including the dependence of frequency noise on the cavity length. Frequency stabilization to a high-finesse reference cavity is demonstrated reducing the linewidth to about 20 - 30 kHz. Yellow light (> 3 mW) at 578 nm was generated by frequency doubling in an enhancement cavity containing a PPLN crystal. The source has potential application for precision spectroscopy of ultra-cold Yb atoms and molecular hydrogen ions.