Inverted n–p junction 940-nm vertical-cavity surface-emitting laser arrays consisting of 875 devices on p-GaAs substrate

Abstract

The authors demonstrate a large-area vertical-cavity surface-emitting laser (VCSEL) 25 × 35 array on a p-type GaAs substrate with an emission wavelength of ∼940 nm and optical output power > 1 W, using an inverted junction (n-up) epitaxial structure for emerging sensing applications. The electrical characteristic (series resistance) of the inverted n–p VCSELs is better than that of standard p–n VCSELs, but optical characteristics (the threshold current density and slope efficiency) are worse possibly due to crystalline defects originating from the p-type substrate whose effect could be avoided in small-area VCSELs. Other inverted junction structures on an n-type substrate are needed for further development. © 2024 The Authors. Electronics Letters published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.