Monolithic integration of 940 nm AlGaAs distributed Bragg reflectors on bulk Ge substrates

TL;DR

This paper demonstrates the successful monolithic growth of high-quality 940 nm AlGaAs DBRs on bulk Ge substrates, enabling scalable VCSEL fabrication with comparable optical properties to traditional GaAs-based structures.

Contribution

It introduces a novel monolithic integration method of AlGaAs DBRs on Ge substrates, expanding the potential for scalable VCSEL production.

Findings

Ge-DBRs have comparable reflectivity spectra to GaAs-based DBRs.

Ge-DBRs exhibit smooth morphology, reasonable periodicity, and uniformity.

The results support VCSEL growth on bulk Ge substrates for large-scale manufacturing.

Abstract

High quality 940 nm Al$_x$Ga$_{1-x}$As n-type distributed Bragg reflectors (DBRs) were successfully monolithically grown on off-cut Ge (100) substrates. The Ge-DBRs have reflectivity spectra comparable to those grown on conventional bulk GaAs substrates and have smooth morphology, reasonable periodicity and uniformity. These results strongly support VCSEL growth and fabrication on more scalable bulk Ge substrates for large scale production of AlGaAs-based VCSELs.