Optically pumped GeSn micro-disks with 16 % Sn lasing at 3.1 um up to 180K

TL;DR

This paper reports on GeSn micro-disks with high Sn content that achieve lasing at 3.1 um up to 180 K, demonstrating improved wavelength and temperature performance for integrated silicon photonics.

Contribution

It introduces high Sn content GeSn micro-disks with optimized crystalline quality that lase at longer wavelengths and higher temperatures than previous GeSn lasers.

Findings

Lasing at 3.1 um wavelength up to 180 K.

Threshold of 377 kW/cm2 at 25 K.

Use of graded Sn buffers improves crystalline quality.

Abstract

Recent demonstrations of optically pumped lasers based on GeSn alloys put forward the prospect of efficient laser sources monolithically integrated on a Si photonic platform. For instance, GeSn layers with 12.5% of Sn were reported to lase at 2.5 um wavelength up to 130 K. In this work, we report a longer emitted wavelength and a significant improvement in lasing temperature. The improvements resulted from the use of higher Sn content GeSn layers of optimized crystalline quality, grown on graded Sn content buffers using Reduced Pressure CVD. The fabricated GeSn micro-disks with 13% and 16% of Sn showed lasing operation at 2.6 um and 3.1 um wavelengths, respectively. For the longest wavelength (i.e 3.1 um), lasing was demonstrated up to 180 K, with a threshold of 377 kW/cm2 at 25 K.