Substantial gain enhancement for optical parametric amplification and oscillation in two-dimensional χ^(2) nonlinear photonic crystals

Abstract

Abstract:We have analyzed optical parametric interaction in a 2D NPC. While in general the nonlinear coefficient is small compared to a 1D NPC, we show that at numerous orientations a multitude of reciprocal vectors contribute additively to enhance the gain in optical parametric amplification and oscillation in a 2D patterned crystal. In particular, we have derived the effective nonlinear coefficients for common-signal amplification and common-idler amplification for a tetragonal inverted domain pattern. We show that in the specific case of signal amplification with QPM by both G 10 and G 11 , symmetry of the crystal results in coupled interaction with the corresponding signal amplification by G 10 and G 1,-1 . As a consequence, this coupled utilization of all three reciprocal vectors leads to a substantial increase in parametric gain. Using PPLN we demonstrate numerically that a gain that comes close to that of a 1D QPM crystal could be realized in a 2D NPC with an inverted tetragonal domain pattern. This special mechanism produces two pairs of identical signal and idler beams propagating in mirror-imaged forward directions. In conjunction with this gain enhancement and multiple beams output we predict that there is a large pulling effect on the output wavelength due to dynamic signal build-up in the intrinsic noncollinear geometry of a 2D NPC OPO. References and links 1.V. Berger, "Nonlinear photonic crystals", Phys. Rev. Lett. 81, No. 19, 4136-4139 (1998

Experimental study of multiwavelength parametric generation in a two-dimensional periodically poled lithium tantalate crystal

“…Our calculations indicate that these wavelengths are due to three QPM processes achieved by the lattice vectors K 1-1 , K 10 , and K 11 , respectively. We notice that, as theoretically predicted [8], the wavelength due to the contribution of K 10 is much more powerful than those due other lattice vectors: K 11 and K 1-1 . Furthermore, we observe that the signal wavelengths due to the contribution of the lattice vectors K 11 and K 1-1 are not symmetrical with respect to the collinear wavelength due to K 10 contribution, as expected [1].…”

“…This is because they contain more lattice vectors [6,7]. Furthermore, Liu and Kung [8] reported, by a numerical study, that a gain enhancement can be reached through the contribution of multiple lattice vectors to phase-match the same nonlinear process. Moreover, Xu et al [9] reported simultaneous optical parametric oscillation and intracavity second harmonic generation based on a hexagonally PPLT crystal.…”

Angular-tuning of optical parametric generation efficiency in 2D periodically poled lithium tantalate

“…Consequently, the 2D structure provides a much greater flexibility to phase-match more than one nonlinear process [4][5][6] . The effective nonlinear coefficient χ (2) is smaller than in the case of 1D periodically poled crystals, which means that the conversion efficiency is also smaller.…”

“…However, a large number of reciprocal vectors involved in the phase matching may act together for the same nonlinear process. Consequently, the overall conversion efficiency is substantially enhanced and could approach the one of the 1D case 4 From the material point of view Lithium Niobate (LiNbO 3 ) and Lithium Tantalate (LiTaO 3 ) 7-9 are very attractive nonlinear crystals. They offer improved flexibility to waveguide implementation by different methods [10][11][12] , and ability to polarization reversal [13][14][15] .…”

Multi-resonant optical parametric oscillator based on 2D-PPLT nonlinear photonic crystal

“…In the general case, we consider that the pump wave vector has a little tilt angle θ p with respect to the grating vector a along the x-axis, and by the same way, the signal and idler waves are generated with noncollinear angles θ s and θ i , respectively. The theoretical study developed by Liu and Kung [21] demonstrated by numerical simulations that a gain enhancement of optical parametric amplification and oscillation in 2D-PPLN can be obtained through the contribution of multiple lattice vectors to the QPM scheme of the same nonlinear process. Thus, in 2009, Xu et al [22] used a 2D periodically poled lithium tantalate (2D-PPLT) crystal with a hexagonal pattern for achieving an autodoubled OPO.…”