Sinko Anton, Solyankin Peter, Kargovsky Aleksey, Manomenova Vera, Rudneva Elena, Kozlova Natalia, Sorokina Natalia, Minakov Fedor, Kuznetsov Sergei, Nikolaev Nazar, Surovtsev Nikolay, Ozheredov Ilya, Voloshin Alexey, Shkurinov Alexander
Faculty of Physics, Lomonosov Moscow State University, GSP-1, 1-2 Leninskiye Gory, Moscow, Russia, 119991.
Institute on Laser and Information Technologies - Branch of the Federal Scientific Research Center "Crystallography and Photonics" of the Russian Academy of Sciences, Svyatoozerskaya Str. 1, Shatura, Russia, 140700.
Sci Rep. 2021 Dec 6;11(1):23433. doi: 10.1038/s41598-021-02862-3.
In this paper we describe the properties of the crystal of guanylurea hydrogen phosphate (NH[Formula: see text])[Formula: see text]CNHCO(NH[Formula: see text])H[Formula: see text]PO[Formula: see text] (GUHP) and propose its application in terahertz photonics and optoelectronics. GUHP crystal has a wide window of transparency and a high optical threshold in the visible and NIR spectral regions and narrow absorption bands in the terahertz frequency range. The spectral characteristics of absorption and refraction in the THz range were found to be strongly dependent on crystal temperature and orientation. Computer simulations made it possible to link the nature of the resonant response of the medium at THz frequencies with the molecular structure of the crystal, in particular, with intermolecular hydrogen bonds and the layered structure of the lattice. The possibility of application of the crystal under study for the conversion of femtosecond laser radiation from visible an NIR to terahertz range was demonstrated. It was shown that dispersion properties of the crystal allow the generation of narrow band terahertz radiation, whose spectral properties are determined by conditions close to phase matching. The properties of the generated terahertz radiation under various temperatures suggest the possibility of phonon mechanism of enhancement for nonlinear susceptibility of the second order.
在本文中，我们描述了磷酸胍脲晶体（NH[化学式：见原文]）[化学式：见原文]CNHCO(NH[化学式：见原文])H[化学式：见原文]PO[化学式：见原文]（GUHP）的性质，并提出其在太赫兹光子学和光电子学中的应用。GUHP晶体在可见光和近红外光谱区域具有宽透明窗口和高光学阈值，在太赫兹频率范围内具有窄吸收带。发现太赫兹范围内的吸收和折射光谱特性强烈依赖于晶体温度和取向。计算机模拟使得将太赫兹频率下介质的共振响应性质与晶体的分子结构，特别是与分子间氢键和晶格的层状结构联系起来成为可能。证明了所研究的晶体用于将飞秒激光辐射从可见光和近红外转换到太赫兹范围的可能性。结果表明，晶体的色散特性允许产生窄带太赫兹辐射，其光谱特性由接近相位匹配的条件决定。在不同温度下产生的太赫兹辐射的性质表明了二阶非线性极化率增强的声子机制的可能性。
