Permanent computer-generated holograms embedded in silica glass by femtosecond laser pulses.

We present a novel technique to directly fabricate permanent computer-generated holograms inside silica glass with femtosecond laser pulses. The Fourier transform of an object is performed using a computer and the complex amplitude distribution is encoded by the detour phase method. The resulted cell-oriented hologram is directly written inside a bulk of silica glass by femtosecond laser-induced microexplosion. The image is then reconstructed with a collimated He-Ne laser beam.