Electrically Injected mid-infrared GeSn laser on Si operating at 140 K

TL;DR

This paper reports the development of electrically injected GeSn lasers on silicon operating at 140 K, demonstrating improved threshold and power characteristics for mid-infrared applications.

Contribution

It presents the first electrically injected GeSn lasers on Si with operation up to 140 K, using optimized cavity design to reduce threshold and enhance power.

Findings

Maximum operating temperature of 140 K with lasing at 2722 nm

Lasing threshold of 0.756 kA/cm2 at 77 K

Peak power of 2.2 mW per facet at 77 K

Abstract

Owing to its true direct bandgap and tunable bandgap energies,GeSn alloys are increasingly attractive as gain media for mid-IR lasers that can be monolithically integrated on Si. Demonstrations of optically pumped GeSn laser at room under pulsed condition and at cryogenic temperature under continuous-wave excitation show great promise of GeSn lasers to be efficient electrically injected light sources on Si. Here we report electrically injected GeSn lasers using Fabry-Perot cavity with 20, 40, and 80 micron ridge widths. A maximum operating temperature of 140 K with lasing threshold of 0.756 kA/cm2 at 77 K and emitting wavelength of 2722 nm at 140 K was obtained. The lower threshold current density compared to previous works was achieved by reducing optical loss and improving the optical confinement. The peak power was measured as 2.2 mW/facet at 77 K.