We demonstrate a simple, femtosecond-scale wavelength tunable, subwavelength-thick nanostructure that performs efficient wavelength conversion from the infrared to the ultraviolet. The output wavelength can be tuned by varying the input power of the infrared pump beam and/or relative delay of the control beam with respect to the pump beam, and does not require any external realignment of the system. The nanostructure is made of chalcogenide glass that possesses strong Kerr nonlinearity and high linear refractive index, leading to strong field enhancement at Mie resonances. Although, as many other materials, chalcogenide glasses absorb in the ultraviolet range, fundamental phase-locking mechanism between the pump and the inhomogeneous portion of the third-harmonic signal enables ultraviolet transmission with little or no absorption.

中文翻译：

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不透明非线性纳米结构中的全光可调谐波长转换

我们展示了一种简单的、飞秒级波长可调谐、亚波长厚的纳米结构，它可以执行从红外线到紫外线的有效波长转换。输出波长可以通过改变红外泵浦光束的输入功率和/或控制光束相对于泵浦光束的相对延迟来调整，并且不需要系统的任何外部重新对准。纳米结构由具有强克尔非线性和高线性折射率的硫属化物玻璃制成，导致在 Mie 共振处的强场增强。尽管与许多其他材料一样，硫属化物玻璃在紫外范围内有吸收，但泵与三次谐波信号的不均匀部分之间的基本锁相机制使得紫外传输几乎没有吸收。