Electro-optically tunable self-focusing and self-defocusing in KTP crystals by a cascaded second-order process  

作　　者：Ruma Debnath Digvijay Singh Hada Susheel Kumar Beda Ardhendu Saha 

机构地区：[1]Department of Electrical Engineering, National Institute of Technology,Agartala

出　　处：《Chinese Optics Letters》2016年第12期103-107,共5页中国光学快报（英文版）

摘　　要：We report the transformation of a linear electro-optically tunable non-phase-matched second-order nonlinear process into a cascaded second-order nonlinear process in a bulk KTP crystal to generate the effect of electrooptically tunable Kerr-type nonlinearity. By applying an electric field on the x–y plane, parallel to the z-axis of the crystal, phase mismatch is created, which introduces a nonlinear phase shift between the launched and reconverted fundamental waves from the generated second harmonic wave. Due to the nonuniform radial intensity distribution of a Gaussian beam, a curvature will be introduced into the fundamental wavefront, which focuses or defocuses the incident beam while propagating through the crystal.We report the transformation of a linear electro-optically tunable non-phase-matched second-order nonlinear process into a cascaded second-order nonlinear process in a bulk KTP crystal to generate the effect of electrooptically tunable Kerr-type nonlinearity. By applying an electric field on the x–y plane, parallel to the z-axis of the crystal, phase mismatch is created, which introduces a nonlinear phase shift between the launched and reconverted fundamental waves from the generated second harmonic wave. Due to the nonuniform radial intensity distribution of a Gaussian beam, a curvature will be introduced into the fundamental wavefront, which focuses or defocuses the incident beam while propagating through the crystal.

关 键 词：tunable cascaded optically focusing wavefront applying nonlinearity created harmonic matching 

分 类 号：O734[理学—晶体学]