Experimental investigation of optical parametric generation enhancement in nonlinear photonic crystal of LiTaO3

We investigated angle-resolved optical parametric generation (OPG) in 2D periodically poled lithium tantalate (PPLT) with a 8.52 m square lattice structure. Substantial parametric gain was observed at two specific incident angles of 0.8 ◦ and 1.6 ◦ , with the signal/idler wave propagating collinearly/non-collinearly to a 532 nm pump. These phenomena are due to simultaneous quasi-phase-matching OPG processes involved contribution from the reciprocal lattice vectors of ( K 1 , 0 and K 1 , 1 ) or ( K 1 , 0 and K 1 , 2 ), respectively. These configurations raise the parametric gain to comparable to that of the 1D QPM structure.