Optical Design of InAlGaAs Low-Loss Tunnel-Junction Apertures for Long-Wavelength Vertical-Cavity Lasers

We report on the optical design of thin selectively etched InAlGaAs tunnel-junction apertures for the realization of optically efficient long-wavelength vertical-cavity surface-emitting lasers (VCSELs). These apertures were designed to introduce minimal optical loss to the structure, facilitate single-mode operation, and yield optical mode diameters that better match the injected current density profile. We then demonstrate InP-based VCSELs emitting at 1304 nm utilizing these low-loss InAlGaAs apertures, resulting in optically efficient low-loss devices with differential quantum efficiencies of up to 60%.