26 W optically-pumped semiconductor disk laser operating at 157-μm using wafer fusion

Abstract

We report a wafer fused high power optically pumped semiconductor disk laser incorporating InP-based active medium fused to a GaAs/AlGaAs distributed Bragg reflector. A record value of over 2.6 W of output power in a spectral range around 1.57 microm was demonstrated, revealing the essential advantage of the wafer fusing technique over monolithically-grown all-InP-based structures. The presented approach allows for integration of lattice-mismatched compounds, quantum-well and quantum-dot based media. This would provide convenient means for extending the wavelength range of semiconductor disk lasers.

Design and Realization of Novel GaAs Based Laser Concepts

“…A deviation from this optimum temperature results in strongly inferior differential efficiencies, and altered threshold values [Ger03,Smi04,Kim06,Fan07b]. Additionally, the VECSEL emission wavelength can shift strongly upon temperature changes [Kon07,Rau08]. As the incident optical pump power is altered to change the output-power level, the heat input is also altered.…”

VECSEL Semiconductor Lasers: A Path to High‐Power, Quality Beam and UV to IR Wavelength by Design

“…InP material system is important because of its access to the 1500-1600 nm telecom wavelength emission range. Improved VECSEL laser performance at these wavelengths has been achieved by bonding or fusing InP-based gain region wafers with high-reflectivity GaAs-based Bragg mirror wafers [97,98]. No lattice matching is required for this wafer fusion approach, thus broadening the choices available for laser emission wavelength materials and mirror materials.…”

“…For example, the 808 nm wavelength pump lasers, the standard pumping wavelength for Nd:YAG solid-state lasers and thus wavelength where pump diodes are easily available, have been used for VECSEL lasers emitting in the 920-1300 nm wavelength range [18,67,68,87]. The common 980 nm pump lasers, the standard wavelength for pumping Er-doped fiber amplifiers, have been used to pump 1550 nm VECSELs [97]. Pump lasers at 790, 808, 830, and 980 nm have been used to pump 2.0-2.3 mm lasers [81,94,105,106].…”

“…But metamorphic and dielectric materials have poor thermal conductivity and such mirrors still have higher than desired thermal impedance. A novel way to overcome this material limitation is to use wafer fusion [97,98]. In this approach, lattice-matched laser mirrors are grown on one substrate in a semiconductor material system with available high index contrast materials, while the gain medium is grown on a different substrate in another material system with the desired output wavelength range.…”

“…The laser mirror and laser gain wafers with different lattice constants are then fused together; this is again much simpler for optically pumped structures where no current injection is required across the fusion interface. A dramatically improved output power performance, from 0.8 to 2.6 W CW, of 1.3 and 1.57 mm VECSELs was demonstrated using such an approach with InP-based gain wafer fused with GaAs/AlAs-based mirror wafer [97,98]. Figure 1.5 shows an example of the full semiconductor window-on-substrate wafer structure of a 980 nm VECSEL.…”