Development of Alignment Technology for Segmented Grating

The alignment method of segmented grating for large scale pulse compressor in high energy glass laser system has been investigated. The final goal of development is about 2 m long grating for 40 cm x 40 cm beam pulse compressor. The elementary technology for adjusting 2 separate gratings was studied in small scale experiments using 25 x 25 mm gratings. We considered the alignment freedom and measured the wave-front and the far-field pattern of segmented grating at Littrow angle with an interferometer. The adjustment of angle and piston provided a well controlled wave-front and far-field pattern.