Study on blazed grating array for beam shaping of laser diode array

The theory of beam shaping of laser diode array (LDA) is described and a beam-shaping system composed of two blazed grating arrays is presented. The system can theoretically transform the beam parameter product (BPP) of LDA into 5.7 mm·mrad in the fast axis and 8.9 mm·mrad in the slow axis. Experimental results indicate the BPP of the fast axis can be transformed into 12 mm·mrad and 9.5 mm·mrad for the slow axis after beam shaping. The beams can be coupled into the fiber of 200 μm diameter and numerical aperture of 0.22 after focused.