Generation of blue light by sum-frequency generation of a spectrally combined broad-area diode laser array.

We present the first demonstration of a spectrally beam combined diode laser array with subsequent sum-frequency generation (SFG). The combined beam of the diode laser array with 19 emitters has the same beam quality as a single emitter, and the wavelength of each emitter is different. The blue light is generated by sum-frequency mixing of pairs of emitters in the diode laser array. About 93 mW of blue light power is produced using a PPLN crystal. Compared with the SFG of two emitters, this approach can increase the number of lasers participating in nonlinear frequency conversion. Thus, it can enhance the available power.