A monoclinic semiorganic molecular crystal GUHP for terahertz photonics and optoelectronics

AbstractIn this paper we describe the properties of the crystal of guanylurea hydrogen phosphate (NH$$_2$$ 2 )$$_2$$ 2 CNHCO(NH$$_2$$ 2 )H$$_2$$ 2 PO$$_3$$ 3 (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.

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A Monoclinic Semiorganic Molecular Crystal GUHP for Terahertz Photonics and Optoelectronics

10.21203/rs.3.rs-833897/v1 ◽

2021 ◽

Author(s):

Anton Sinko ◽

Peter Solyankin ◽

Aleksey Kargovsky ◽

Vera Manomenova ◽

Elena Rudneva ◽

...

Keyword(s):

Terahertz Radiation ◽

Narrow Band ◽

Nonlinear Susceptibility ◽

Phase Matching ◽

Terahertz Frequency ◽

Frequency Range ◽

Hydrogen Phosphate ◽

Terahertz Frequency Range ◽

Absorption Bands ◽

Phonon Mechanism

Abstract In this paper we describe the properties of the crystal of guanylurea hydrogen phosphate (NH2)2CNHCO(NH2)H2PO3 (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 IR spectral regions and narrow absorption bands in the terahertz frequency range. The possibility of application of the crystal under study for the conversion of femtosecond laser radiation from visible an IR 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.

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Photothermal, Photoelectric, and Photothermoelectric Effects in Bi-Sb Thin Films in the Terahertz Frequency Range at Room Temperature

Photonics ◽

10.3390/photonics8030076 ◽

2021 ◽

Vol 8 (3) ◽

pp. 76

Author(s):

Mikhail K. Khodzitsky ◽

Petr S. Demchenko ◽

Dmitry V. Zykov ◽

Anton D. Zaitsev ◽

Elena S. Makarova ◽

...

Keyword(s):

Thin Films ◽

Terahertz Radiation ◽

Room Temperature ◽

Voltage Drop ◽

Radiation Detection ◽

Radiation Detectors ◽

Thz Radiation ◽

Terahertz Frequency ◽

Frequency Range ◽

Terahertz Frequency Range

The terahertz frequency range is promising for solving various practically important problems. However, for the terahertz technology development, there is still a problem with the lack of affordable and effective terahertz devices. One of the main tasks is to search for new materials with high sensitivity to terahertz radiation at room temperature. Bi1−xSbx thin films with various Sb concentrations seem to be suitable for such conditions. In this paper, the terahertz radiation influence onto the properties of thermoelectric Bi1−xSbx 200 nm films was investigated for the first time. The films were obtained by means of thermal evaporation in vacuum. They were affected by terahertz radiation at the frequency of 0.14 terahertz (THz) in the presence of thermal gradient, electric field or without these influences. The temporal dependencies of photoconductivity, temperature difference and voltage drop were measured. The obtained data demonstrate the possibility for practical use of Bi1−xSbx thin films for THz radiation detection. The results of our work promote the usage of these thermoelectric materials, as well as THz radiation detectors based on them, in various areas of modern THz photonics.

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