Recent Progress on 1.55-m Dilute-Nitride Lasers

Abstract—We review the recent developments in GaAs-based 1.55- m lasers grown by molecular beam epitaxy (MBE). While materials growth is challenging, the growth window appears to be relatively broad and is described in detail. The key con-siderations for producing high-quality GaInNAsSb material emitting at 1.55- m regime are examined, including the nitrogen plasma conditions, ion removal from the nitrogen flux, surfactant-mediated growth, the roles of various V–III ratios, the growth temperature, the active region thermal budget, proper annealing, and composition. We find that emission may be tuned throughout the 1.55- m communications band without penalty to the optical quality varying only one parameter—the total growth rate. This powerful result is validated by the demonstration of low-threshold edge-emitting lasers throughout the 1.55- m regime, including threshold current densities as low as 318 A/cm2 at 1.54 m. Addi-tional characterization by Z-parameter techniques, cavity length studies, and band offset measurements were performed to better understand the temperature stability of device performance. Lasing was extended as far as 1.63 m under nonoptimized growth conditions. The GaAs-based dilute-nitrides are emerging as a very promising alternative to InP-based materials at 1.55- m due to their high gain, greater range of achievable band offsets, as well as the availability of lattice-matched AlAs–GaAs materials and native oxide layers for vertical-cavity surface-emitting lasers (VCSELs). Indeed, this effort has enabled the first electrically injected C-band VCSEL on GaAs. Index Terms—1.55 m, Annealing, auger recombination, con-tinuous wave (CW), dilute nitride, GaInNAs, GaInNAsSb, galliu