Abstract

The conversion efficiency of cross-polarized wave (XPW) generation can be improved using two separate thinner nonlinear crystals versus a single thick one, due to the evolution of the beam sizes and individual phases after the first crystal. In this paper, we present an alternative scheme in which a curved mirror is used to reimage a plane just after the ${\mathrm{BaF}}_2$ crystal for a second pass. We also develop a simple analytic model for XPW conversion that describes the origin of a nonlinear phase mismatch and nonlinear lensing for both the fundamental wave and XPW. Coupled with the numerical solution for the process and the Fresnel propagation after the first pass, we also explore the factors that affect the efficiency of saturated, seeded XPW conversion. These include the development of the on-axis relative phase difference in the first crystal and after it (during free-space propagation), mode matching, wavefront curvature difference, and crystal tuning angle. We also experimentally demonstrate that the beam quality of the XPW signal after the second pass can be improved by the reimaging.

© 2015 Optical Society of America

Two crystal arrangement to fight efficiency saturation in cross-polarized wave generation

A. Jullien, O. Albert, G. Chériaux, J. Etchepare, S. Kourtev, N. Minkovski, and S. M. Saltiel
Opt. Express 14(7) 2760-2769 (2006)

Spatiotemporal polarization pattern obtained by interference in a single cross-polarized wave-generation crystal

Ferran Cambronero-López, Carmen Bao-Varela, and Camilo Ruiz
J. Opt. Soc. Am. B 33(8) 1740-1748 (2016)

Nonlinear polarization rotation of elliptical light in cubic crystals, with application to cross-polarized wave generation

Aurélie Jullien, Olivier Albert, Gilles Chériaux, Jean Etchepare, Stoyan Kourtev, Nikolay Minkovski, and Solomon M. Saltiel
J. Opt. Soc. Am. B 22(12) 2635-2641 (2005)

Improved nonlinear cross-polarized wave generation in cubic crystals by optimization of the crystal orientation

S. Kourtev, N. Minkovski, L. Canova, A. Jullien, O. Albert, and S. M. Saltiel
J. Opt. Soc. Am. B 26(7) 1269-1275 (2009)

Efficient cross polarized wave generation for compact, energy-scalable, ultrashort laser sources

L.P. Ramirez, D.N. Papadopoulos, A. Pellegrina, P. Georges, F. Druon, P. Monot, A. Ricci, A. Jullien, X. Chen, J.P. Rousseau, and R. Lopez-Martens
Opt. Express 19(1) 93-98 (2011)