Multi-Watt Semiconductor Disk Laser by Low Temperature Wafer Bonding

Abstract

We present wafer bonding techniques applied for the first time in integrating GaAs-based distributed Bragg reflectors (DBRs) with InP-based active regions in optically pumped semiconductor disk lasers. The bonding procedures are performed at a modest temperature of 200°C and enable multiwatt output powers from 1.3 µm semiconductor disk lasers. These technologies are critical for vertical-cavity lasers emitting in the range 1.3-1.6 µm since monolithically grown lattice-matched InP structures suffer from DBRs with low refractive index contrast and poor thermal conductivity when compared with GaAs-based DBRs.Index Terms-Low temperature wafer bonding, molecular beam epitaxy (MBE), semiconductor disk laser (SDL).

Optically pumped VECSELs: review of technology and progress

“…As for their performance, wafer-bonded VECSELs with intermediate layers are considerably less studied than wafer-fused VECSELs. However, the reported output powers of 3-4 W at 1.32 µm [131,171] correspond to the performance of similar wafer-fused structures [47]. Moreover, while being far from a definite comparison, this observation of similar performance is strengthened by the thermal simulations of wafer-bonded VECSELs [56].…”

“…On the other hand, the wafer-bonded VECSELs using self-assembling monolayers utilize a thin SiO 2 layer and a monolayer of (3-mercaptopropyl)trimethoxysilane (MPTMS) [171]. The bonding process is started by activating the SiO 2 -covered GaAs-based DBR with ammonia as before, after which the DBR is placed in a low-vacuum chamber with an open container of MPTMS [190].…”