Variable surface profile gratings in sol-gel glass fabricated by holographic interference

Holographic interference is widely used for fabrication of sinusoidal gratings in photosensitive optical material. We present variable surface profile gratings fabricated in photosensitive hybrid sol-gel glass by use of holographic interference. It is found by experiment that different surface profiles of gratings including sinusoidal, binary, and two-peak sinusoidal can be obtained by precise control of exposure time. The experimental results are helpful for researchers fabricating gratings by holographic interference.