A composite transmission pulse compression grating was proposed for femto-second Ti:sapphire lasers. The composite transmission grating with 700-900 nm bandwidth worked at a center wavelength of 800 nm was consisted of two gratings with groove densities 1 250 line/mm and 3 300 line/mm and they were integrated in a fused silica plate. The 1 250 line/mm grating was used for compressing laser pulse. The 3 300 line/mm anti-reflection grating was conductive to decreasing the reflection loss and avoiding the wave-front distortion by using a high frequency grating structure to replace the anti-reflection film on the surface of the fused silica plate. Completely being made of fused silica

the composite pulse compression grating has a high laser damage threshold. The composite transmission grating was designed based on the rigorous coupled wave theory. The optimization calculation results show that the -1st order diffraction efficiency of the 1 250 line/mm grating is up to 98% (@800 nm) and the transmission of the 3 300 lp/mm grating is up to 99.7% at 700-900 nm bandwidth. Finally

the composite transmission pulse compression grating (

Φ

65 mm×1 mm) was fabricated by holographic recording and ion bean etching and its diffraction efficiency is coincident with that of the theoretical analysis.