Substrate-etched high power external-cavity surface-emitting lasers

To decrease the thermal effect of a vertical-external-cavity surface-emitting laser and increase its output power,a high thermal conductivity SiC heatspreader was bond on the reverse-order semiconductor wafer with the capillary method,and then the substrate was removed by means of chemical etch.The characteristics of the laser formed by the substrate-etched wafer were experimentally studied.When the active region in the gain structure is InGaAs/AlGaAs multiple quantum wells,the pump source is a fiber-coupled 808nm diode laser,and the transmission of the output coupler is 3% at laser wavelength,the TEM00 mode output power of 0.52W and the optical-to-optical conversion efficiency of 20% are obtained at room temperature.The laser wavelength is 1018nm,and the spectrum width is 2nm(full width half maximum).The measured M2 factor in x and y direction of 1.01 and 1.00 demonstrate the near diffraction-limited Gaussian beam of the laser.It can be concluded that the substrate-etching technology can significantly improve the thermal property of vertical-external-cavity surface-emitting lasers and results in high power and high beam quality.