Authors: Daniel Jedrzejczyk Reiner Güther Katrin Paschke Götz Erbert Günther Tränkle
Publish Date: 2012/09/21
Volume: 109, Issue: 1, Pages: 33-42
Abstract
In this work we investigate experimentally and theoretically limitations of highly efficient highpower singlepass secondharmonic generation process in a quasiphase matched magnesium oxidedoped lithium niobate ridge waveguide due to structural imperfections optical absorption and resulting heat generation With the distributed Bragg reflector diode laser emitting at 1061 nm applied in the presented benchtop experiment a coupling efficiency into the ridge waveguide nonlinear device of 86 is realized An internal normalized conversion efficiency of 375 Wcm21 is determined A maximum secondharmonic power of 386 mW is reached at a corresponding optooptical and electrooptical conversion efficiency of 38 and 95 respectively A saturation of the conversion efficiency at a high power level as well as its dependency on the nonlinear device structure inhomogeneity are confirmed experimentally With a theoretical model incorporating geometrical inhomogeneity linear and nonlinear absorption and resulting heat load the secondharmonic generation in a ridge waveguide can be simulated realistically Increased values of nonlinear absorption coefficients higher than until now reported lead to a very good agreement between theoretical and experimental results Moreover according to the simulation structural inhomogeneities can enhance the SHG conversion efficiency at high output powers
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