Dual-wavelength vertical external-cavity surface-emitting laser: strict growth control and scalable design

Abstract

This paper reports on the design and fabrication of a dual-wavelength vertical external-cavity surface-emitting laser. Grown by molecular beam epitaxy, the laser structures have a relatively simple active region divided into two sections, between which there is no optical filter. Comparable threshold power was achieved for both wavelengths. The growth rate was controlled precisely by growing AlAs/GaAs superlattices with different period thicknesses and testing them with high-resolution X-ray diffractometry. The simultaneous emission of two wavelengths was detected in setup without a heat spreader, one of 991 nm and the other of 1038 nm. After diamond heat spreader was bonded, both wavelengths lased in continuous-wave mode with the combined output power of 1.79 W. The design scalability allowed us to obtain two further structures with layers thinned by about 3 % in the first and by about 6 % in the second, operating at 958/1011 and 928/977 nm, respectively.