GeSn Nanobeam Light-Emitting Diode as a GHz-Modulated Light Source

Abstract

Designs and theoretical analysis are presented for a room temperature resonant-cavity-enhanced GeSn LED whose emission peaks at the 2 $\mu$m wavelength. The Ge/GeSn/Ge PIN hetero-diode of length 1 $\mu$m is embedded in a rib-type Ge-on-Si nanobeam having either 24 or 36 air holes. The maximum LED modulation bandwidth $f_{3\text{dB}}$ is proportional to the Purcell factor and is inversely proportional to $\tau _{s\,p0}$ the GeSn bulk spontaneous emission lifetime. For an emission linewidth of 200 nm and $\tau _{s\,p0}$ of 10 ns, an $f_{3\text{dB}}$ of 1.6 GHz is predicted.

Keywords

• Light emitting diodes
• electrooptic devices
• photonic crystals