Optical investigation of femtosecond laser induced microstress in neodymium doped lithium niobate crystals

RODENAS A , GARCIA JAS , JAQUE D TORCHIA, MENDEZ C , ARIAS I , ROSO L, AGULLO-RUEDA F

JOURNAL OF APPLIED PHYSICS

Año: 2006 vol. 100 p. 1 - 8

0021-8979

The depth-resolved micromodification of single-crystalline femtosecond laser irradiated Nd3+ doped MgO:LiNbO3 crystals is investigated by means of micro-Raman and microluminescence experiments. We have found that a permanent tensile stress of the order of 2 GPa is induced in the vicinity of ablated volume as a consequence of the pressure-wave propagation due to the thermoelastic relaxation of the laser irradiated material. Microluminescence experiments have revealed that, as a consequence of the permanent laser induced microstress, a localized redshift of the F-4(3/2)-> I-4(9/2) luminescence band of Nd3+ ions also takes place due to a crystal field modification. The analysis of Raman and fluorescence bandwidths indicates that a slight lattice disorder and densification is induced by femtosecond laser irradiation. (c) 2006 American Institute of Physics.