Nonlinear Cherenkov difference-frequency generation exploiting birefringence of KTP

Abstract

In this letter, we demonstrate the realization of nonlinear Cherenkov difference-frequency generation (CDFG) exploiting the birefringence property of KTiOPO4 (KTP) crystal. The pump and signal waves were set to be along different polarizations, thus the phase-matching requirement of CDFG, which is, the refractive index of the pump wave should be smaller than that of the signal wave, was fulfilled. The radiation angles and the intensity dependence of the CDFG on the pump wave were measured, which agreed well with the theoretical ones.

M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In): Introduction of Phosphate Anions into Metal Iodates

“…Furthermore, phosphate groups can be condensed into different polynuclear P x O y groups, [PO 3 ] ∞ infinite chains, or networks, which have greatly enriched the structural chemistry of metal phosphates. , Metal phosphates are generally rigid, resistant to chemical attack, and thermally stable. In addition, many phosphates including KH 2 PO 4 (KDP) and KTiOPO 4 (KTP) are important SHG materials . Thus, it is assumed that the combination of IO 3 – and PO 4 3– anions into a same compound may lead to new types of metal iodates with novel structures and unique physical properties …”

Third-order nonlinear phenomenon generated on the inner surface of bulk lithium niobate crystals with magnesium doping

“…What is more, ultra-short pulses of light can also be observed through the stimulation of sum frequency generated on the domain walls of periodically polarized crystals [4][5][6] . Nonlinear Cherenkov cascading difference frequency [7] , third harmonics, and other higher harmonics [8,9] generated in the superlattice structure have also been the extensive subject of numerous investigations.…”

Nonlinear Cherenkov radiations modulated by mode dispersion in a Ti in-diffused LiNbO_3 planar waveguide

“…By this means, Cherenkov type second harmonic generation (SHG), was experimentally demonstrated in an anomalous dispersive ultra-thin MgO doped LiNbO3 without phase velocity threshold [7]. Following the same idea, Cherenkov type different frequency generation (DFG), which cannot automatically be accomplished in normal dispersion materials, was realized in a KTP crystal [8]. In addition to utilizing the birefringence properties, the mode dispersion in waveguides can be engineered by choosing proper waveguide parameters, thus provide more flexibility in modulating NCRs.…”