Photorefractive non-linear single beam propagation in LiNbO3 waveguides above the optical damage threshold

Photovoltaic laser beam degradation in lithium niobate planar waveguides: two-center model approach

“…In spite of this limitation, the main qualitative features of the experimental far field profile [10] can already be observed, although the diffraction pattern is smoother (smaller contrast between maxima and minima). Anyhow, in order to address more quantitative predictions it is necessary to use a more accurate approach developed in the next section.…”

“…To some extent, the results can be applied to other guide geometries and to bulk crystals. Nevertheless, when photovoltaic charge transport is in the waveguide plane, more complex phenomena than those described here may occur, such as catastrophic optical damage by noise amplification [4][5][6][7][8][9][10][11][12][13][14][15].…”

“…We have applied the algorithm to simulate beam propagation in planar waveguides because there are a variety of well-documented experimental results to compare with theory. Specifically, the numerical simulations will be compared with data on self-defocusing and beam filamentation that have been recently reported [8][9][10][11]. Finally, this method will provide a reliable way to predict the complex phenomena occurring at high light intensities in LiNbO 3 .…”

“…Although it is accepted that this distortion roughly consists in a self-defocusing effect [5][6][7], recent experiments revealed a rich variety of additional nonlinear effects, including filamentation and temporal instabilities [8][9][10][11], that becomes important when the light intensity increases. This range of light intensities should be reached when designing efficient nonlinear optical devices such as second harmonic generators in waveguide configuration [12].…”

Optical damage of Zr:LiNbO3 waveguides produced by proton implantation

“…The optical damage of LiNbO 3 waveguides should be of great importance for their applications at high-intensity circumstance. The optical damage properties of proton exchanged LiNbO3 waveguides were been well referenced [12][13][14][15]. Optical damage of the waveguides formed by He ion implantation in undoped LiNbO 3 was investigated, and the optical damage threshold was determined to be $500 W/cm 2 .…”