One-step generation of a visible to deep-ultraviolet tunable laser from a near-infrared ultrafast light source

【摘要】 For the first time, to our knowledge, the cascading effects of self-phase modulation and second-harmonic generation（SPMSHG） in a nonlinear optical medium were used to conveniently convert a near-infrared ultrafast laser with a fixed center wavelength into a visible to deep-ultraviolet（DUV） laser with a continuously tunable wavelength. When a β-BaB₂O₄（BBO）crystal was used as the nonlinear optical medium, and a Ti:sapphire laser（800 nm, 38 fs） was used as the fundamental light source, the output wavelength had a tunable range of 225–460 nm, and the highest optical conversion efficiency reached 18.1% at 361 nm. For a 1030 nm fundamental light source, the shortest output wavelength was also 225 nm by one-step frequency conversion of the BBO crystal. By further frequency conversions, the tunable wavelength can extend to the vacuum ultraviolet（VUV） waveband, as short as 193 nm. These results demonstrated that SPM-SHG could be used as an extremely simple and effective frequency conversion method to obtain a wideband tunable ultraviolet laser.更多还原

【Abstract】 For the first time, to our knowledge, the cascading effects of self-phase modulation and second-harmonic generation（SPMSHG） in a nonlinear optical medium were used to conveniently convert a near-infrared ultrafast laser with a fixed center wavelength into a visible to deep-ultraviolet（DUV） laser with a continuously tunable wavelength. When a β-BaB₂O₄（BBO）crystal was used as the nonlinear optical medium, and a Ti:sapphire laser（800 nm, 38 fs） was used as the fundamental light source, the output wavelength had a tunable range of 225–460 nm, and the highest optical conversion efficiency reached 18.1% at 361 nm. For a 1030 nm fundamental light source, the shortest output wavelength was also 225 nm by one-step frequency conversion of the BBO crystal. By further frequency conversions, the tunable wavelength can extend to the vacuum ultraviolet（VUV） waveband, as short as 193 nm. These results demonstrated that SPM-SHG could be used as an extremely simple and effective frequency conversion method to obtain a wideband tunable ultraviolet laser.更多还原