Open AccessEnhancement of nonlinear Raman-Nath diffraction in two-dimensional optical superlattice
Author(s) -
Wenjie Wang,
Yan Sheng,
Vito Roppo,
Zhihui Chen,
Xiaoying Niu,
Wiesław Królikowski
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.018671
Subject(s) - optics , diffraction , randomness , physics , raman spectroscopy , modulation (music) , nonlinear optics , phase modulation , nonlinear system , self phase modulation , superlattice , raman scattering , materials science , optoelectronics , mathematics , laser , quantum mechanics , phase noise , statistics , acoustics
We study second harmonic generation via nonlinear Raman-Nath diffraction in an optical superlattice that maintains a periodic modulation of the second-order nonlinear coefficient χ((2)) in transverse direction but undergoes random modulation in longitudinal direction. We show that the random χ((2)) modulation offers a continuous set of reciprocal lattice vectors to compensate for the phase mismatch of nonlinear Raman-Nath diffraction in the longitudinal direction, leading to more efficient harmonic generation for a wide range of wavelengths. We also characterize the intensity dependence of nonlinear Raman-Nath diffraction on the degree of randomness of the optical supperlattice.