TY - JOUR

T1 - Detection of Terahertz Frequencies in S-Doped GaSe Crystals Using Laser Pulses at Telecom Wavelengths

AU - Shevchenko, Olesya N.

AU - Mikerin, Sergey L.

AU - Kokh, Konstantin A.

AU - Nikolaev, Nazar A.

N1 - This research was funded by the Ministry of Science and Higher Education of the Russian Federation: project No. FSUS-2020-0029 (in terms of assessing the potential of employing GaSe crystals in future telecom devices for big data transmission systems); project No. 121032400052-6 (in terms of studying the linear and nonlinear optical properties of the crystals for the terahertz frequency range); and within the state assignment project of the Sobolev Institute of Geology and Mineralogy (in terms of improving the growth technology of doped GaSe crystals). Публикация для корректировки.

PY - 2023/2

Y1 - 2023/2

N2 - Nonlinear optical crystals of gallium selenide are efficient up- and downconverters of infrared and terahertz frequencies. Their nonlinear properties have been investigated at wavelengths within the main transparency window. However, insufficient attention has been paid to studies at the telecommunication wavelength, especially for sulfur-doped crystals. Closing this gap, we report on the optical and electro-optical properties of GaSe(1–x)Sx crystals (where x = 0, 0.03, 0.12, 0.16, and 0.22). For this purpose, the refractive indexes of the ordinary waves at terahertz frequencies and at a wavelength of 1.55 μm have been measured. The detection efficiency of the subterahertz waves in the crystals was studied using Er-fiber laser pulses and compared with that of GaAs, the etalon electro-optical crystal, at this wavelength. This allows us to estimate the dependence of the electro-optic coefficient r22 of GaSe(1–x)Sx on the sulfur concentration. It was shown that the sample with x = 0.12 has the largest value of the electro-optical coefficient r22 = 1.26 pm/V and provides the highest detection efficiency among the samples. The potential of employing S-doped GaSe crystals as nonlinear optical converters for photonic devices operating at telecom wavelengths is discussed.

AB - Nonlinear optical crystals of gallium selenide are efficient up- and downconverters of infrared and terahertz frequencies. Their nonlinear properties have been investigated at wavelengths within the main transparency window. However, insufficient attention has been paid to studies at the telecommunication wavelength, especially for sulfur-doped crystals. Closing this gap, we report on the optical and electro-optical properties of GaSe(1–x)Sx crystals (where x = 0, 0.03, 0.12, 0.16, and 0.22). For this purpose, the refractive indexes of the ordinary waves at terahertz frequencies and at a wavelength of 1.55 μm have been measured. The detection efficiency of the subterahertz waves in the crystals was studied using Er-fiber laser pulses and compared with that of GaAs, the etalon electro-optical crystal, at this wavelength. This allows us to estimate the dependence of the electro-optic coefficient r22 of GaSe(1–x)Sx on the sulfur concentration. It was shown that the sample with x = 0.12 has the largest value of the electro-optical coefficient r22 = 1.26 pm/V and provides the highest detection efficiency among the samples. The potential of employing S-doped GaSe crystals as nonlinear optical converters for photonic devices operating at telecom wavelengths is discussed.

KW - GaSe

KW - electro-optical coefficient

KW - gallium selenide

KW - millimeter waves

KW - refractive index

KW - telecommunication wavelength

KW - terahertz frequencies

KW - terahertz time-domain spectroscopy

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85149301709&origin=inward&txGid=f9b94b971b2d217f085f0539ab40cb94

UR - https://www.mendeley.com/catalogue/911817a6-633c-3134-9f5e-58ec4c6b2955/

U2 - 10.3390/app13042045

DO - 10.3390/app13042045

M3 - Article

VL - 13

JO - Applied Sciences (Switzerland)

JF - Applied Sciences (Switzerland)

SN - 2076-3417

IS - 4

M1 - 2045

ER -