Direct laser writing of diffractive array illuminators operable at two wavelengths

We present a grating array illuminator that serves at two different wavelengths. The grating was designed by simulated annealing method and drawn in photoresist by direct laser lithography that we have developed on optical disk mastering technology. Upon grating reconstruction with two chosen wavelengths, 1064 and 532 nm, from Nd:YAG lasers, two arrays of 9 split beams with the same pitch were reconstructed. The illuminator performance was found rather sensitive to profile errors, which was supported by computer analysis.