Abstract
Highly multimodal nonlinear guided wave approach based on Fourth and Fifth harmonic frequency conversion schemes
using Total Internal Reflection Quasi phase matching is analytically described in a parallel slab geometry of magnesium
oxide doped lithium niobate crystal. The guided wave optics approach provides more accurate and realistic results in
comparison to plane ray optics. Effect of nonlinear law of reflection along with other optical losses like absorption, Goos –
Hänchen -shift and reflection has also been taken into consideration while calculating the conversion efficiency. Various
parametric changes, like variations in slab length and thickness, have also been studied. This scheme significantly
improved the conversion efficiency compared to other approaches (e.g., Cascaded generation, periodic polling) utilized for
the fourth-harmonic frequency conversion scheme. The conversion efficiency of 0.15418% and 0.00859%, corresponding to
the Fourth and Fifth harmonic wavelength of 550 nm and 588 nm, have been observed in a 5 mm and 5.2 mm long crystal,
respectively.
Keywords
Fourth harmonic generation, TIR-QPM, Parallel slab, Uniaxial crystal, MgO: LN, Waveguide, Non-linear guided wave
theory.
Citation
JAYA SAHA, SUMITA DEB, Fourth and Fifth harmonic generation by Total Internal Reflection – quasi phase matching using the light of highly multimodal nonlinear guided wave approach in a parallel slab of Magnesium oxide doped lithium niobate, Optoelectronics and Advanced Materials - Rapid Communications, 19, 1-2, January-February 2025, pp.50-62 (2025).
Submitted at: March 11, 2024
Accepted at: Feb. 3, 2025