Broadband second-harmonic generation in Sr<SUB>x</SUB>Ba<SUB>1 - x</SUB>Nb<SUB>2</SUB>O<SUB>6</SUB> by spread spectrum phase matching with controllable domain gratings

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• Bekker, Alexander
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• Fischer, Baruch

Abstract

We have demonstrated, for the first time to our knowledge, second-harmonic generation for a broad input wavelength range of 750-1064 nm in Sr_xBa_1-xNb₂O₆ crystals, with a controllable spread spectrum of quasiphase matching. Second-harmonic conversion efficiencies of up to ∼1% were observed. This was done without any temperature or angular tuning of the crystal. The phase matching was obtained by inducing alternating ferroelectric domains in the crystal in real time, using a novel fixing process which is based on screening. The broadband capability of the conversion is allowed by a spread in the range of the domain widths.