Multi-Wavelength Vertical Cavity Laser Arrays Grown on a Patterned Backup Substrate

Abstract

The capability to fabricate two-dimensional (2D) semiconductor diode laser array is a key and most important step towards making wafer-scale low-cost lasers. The recent emergence of vertical cavity surface emitting laser (VCSEL) facilitates the fabrication such large 2D arrays. In this paper, I will review recent progress on a novel large-aperture single-mode VCSEL and a 2D multiple-wavelength VCSEL array for ultrahigh bandwidth applications. We demonstrated a passive antiguide region (PAR) VCSEL which emits a stable single mode with very low threshold, a large aperture, and fixed polarization. We also demonstrated multi-wavelength VCSEL arrays with repeatable wavelength spans over 20 nm grown by Molecular Beam Epitaxy. The wavelength shift is achieved by varying the GaAs growth rate across the wafer using a patterned backing wafer to induce a temperature profile. Such multiple wavelength laser arrays are promising for ultra-high bandwidth optical transmission and switching systems using wavelength division multiplexing (WDM).