Threshold Property of Photoresist Film for Two-photon Optical Memory

Two photon threshold property of photoresist films have been studied by changing exposure energy. When photoresist film is irradiated by Ti∶Sapphire laser with wavelength 770 nm, pulse width 130 fs, repetition rate 82 MHz, the damage and recording thresholds of the material are 9 15×10 5 J/cm 2 and below 5 57×10 5 J/cm 2, respectively. The principle experiments of two photon optical memory are demonstrated in photoresist film. The patterns of optical bit data storage are realized at different input power density. The corresponding 3 D tomographies of these recorded spots are scanned under near field optical microscope.