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Formation and partial recovery of optically induced local dislocations inside CaF2 single crystal
Bin Qian1, Juan Song, Guoping Dong
1State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, PR China.
Abstract:
We reported on the formation of a microstructure (skew cross-shaped pattern) in bulk CaF(2) single crystal, which originates from local dislocations and microcracks around the focal point of a single infrared femtosecond laser beam. Relations between morphology of the microstructure and the laser power as well as the number of laser pulses were discussed. Furthermore, it was observed that the optically induced microstructure could be partially erased by additional irradiation of its neighboring area with femtosecond laser pulses. High-resolution transmission electron microscope (HRTEM) observations confirmed the disappearance of some local dislocations after the additional femtosecond laser irradiation.
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