A modified spectral beam combining (SBC) approach based on double asymmetrical filters was proposed. By using this scheme, the high-order lateral modes at the edge of the far-field pattern can be suppressed in the external cavity, and the beam quality in the slow-axis direction was improved from 16.1 to 13.4 compared to the conventional SBC. In the meanwhile, the electrical-to-optical efficiency from the modified SBC was more than 40% with an output power of 34.1 W, which is similar to that of the conventional SBC.

This paper reviewed the development of optically pumped GaSb based semiconductor disk lasers (SDLs) emission at 2 μm wavelength region from the aspects of wavelength extending, power scaling, line-width narrowing and short-pulse generation. Most recently, the wavelength of GaSb based SDLs has been extended to 2.8 μm. The highest output power of the GaSb based SDLs has been reached to 17 W at the temperature of 20 ℃. By using active stabilization, the GaSb based SDL with line-width of 20 kHz and output power of 1 W was realized. Moreover, the shortest pulse obtained from the GaSb based SDLs was generated as short as 384 fs by incorporating semiconductor saturable absorber mirrors (SESAM) in the cavity.

Far-field blooming, a serious far-field dependence on driving current, affects the stability of beam quality and applications of broad-area (BA) diode lasers. In this Letter, the lateral ridge waveguide (LRW) is introduced to BA lasers by a simple and cost-effective approach to control the far-field stability and beam divergence. The influences of LRW length on output power, near- and far-field, are investigated and it is found that the optimized LRW length is able to improve both the far-field blooming and output power. The mechanism behind this is analyzed and a 0.13°/A dependence of lateral divergence angle on the injection current is achieved.

Broad-area diode lasers usually supply high output power but low lateral beam quality. In this Letter, an on-chip combined angled cavity is proposed to realize narrow lateral far field patterns and high brightness. The influence of included angles, emitting facets on output power, and beam quality are investigated. It demonstrates that this V-junction laser is able to achieve a single-lobe far field at optimal cavity length with a 3.4 times improvement in brightness compared with Fabry–Perot (F-P) cavity lasers. The excited high-order modes at a high injection level reduce the brightness, but it is still 107% higher than that of F-P lasers.