One-dimensional spatial soliton families in optimally engineered quasi-phase-matched lithium niobate waveguides

Abstract

The advantage for quadratic soliton generation of engineering the quasi-phase-matching period near the input of lithium niobate slab waveguides is demonstrated. This approach allows members of one-dimensional quadratic soliton families with different values of the wave-vector mismatch to be cleanly excited and to be characterized by quantitative intensity-profile measurements of both the fundamental and the second-harmonic soliton components.

Quadratic spatial solitons

“…An example of how the magnitudes of the fields evolve is shown in Fig. 3 [17]. Note that there are radiation fields generated which propagate away from the region of the soliton resulting in net losses between the input power and the final soliton power.…”

“…Experiments have been reported in LiNbO 3 at 1550 nm with both Type I and QPM phase-matching using fundamental wave only excitation [16,17]. The sample length was 5 cm in these experiments and a narrow bandwidth pulsed laser with pulse width of about 8 ps was used.…”

“…These narrowing processes can counteract diffraction, leading to solitonic propagation. Based on these processes, quadratic spatial solitons have been observed in χ (2) -active slab waveguides and bulk media [16][17][18][19][20][21][22][23]. The newest geometries in which quadratic solitons have been observed have utilized arrays of weakly coupled channel waveguides [24,25].…”

Spatial Solitons in Quadratic 2D Nonlinear Photonic Crystals

“…The original predictions on soliton formation via three-wave mixing [2] were confirmed nearly a decade ago by the first experiments carried out in KTP and LiNbO 3 [3][4]. Since then, the development of QuasiPhase-Matching (QPM) materials such as Periodically Poled LiNbO 3 (PPLN) has opened up new possibilities for quadratic soliton science and engineering [5][6].QPM has also recently been extended to higher-dimensionalities, to demonstrate 2D PPLN Nonlinear Photonic Crystals (NPC), i.e. 2D lattices in the second-order susceptibility χ (2) , enabling novel and more versatile geometries for parametric interactions [7][8].…”

Parametric Solitons in Nonlinear Photonic Crystals

“…The original predictions on soliton formation via three-wave mixing [2] were confirmed nearly a decade ago by the first experiments carried out in KTP and LiNbO 3 [3][4]. Since then, the development of Quasi-Phase-Matching (QPM) materials such as Periodically Poled LiNbO 3 (PPLN) has opened up new possibilities for quadratic soliton science and engineering [5][6]. QPM has also recently been extended to higher-dimensionalities, to demonstrate 2D PPLN Nonlinear Photonic Crystals (NPC), i.e.…”