Experimental study of THz electro-optical sampling crystals ZnSe, ZnTe and GaP

Abstract

Abstract. The application of optoelectronic techniques to the generation and detection of THz radiation is now well established. Wide gap semiconductor crystals of groups II-VI, III-V and III-VI are abundantly used. However, some limitations are occurred while using powerful laser systems. In this paper we introduce experimental results of two-photon absorption (2PA) in ZnSe, ZnTe and GaP studied with femtosecond pump-probe supercontinuum spectroscopy. Using of supercontinuum helps us to measure 2PA absorption dynamics and nonlinear index of refraction in wide frequency ranges. Besides influence of Fe concentration in ZnSe:Fe crystals on transmitted THz radiation is described.

Direct and integrating sampling in terahertz receivers from wafer-scalable InAs nanowires

“…3 e and 3h, respectively. Both spectral responses show a broadband response approaching 3 THz (defined as the cut-off frequency at the noise floor of its spectral response), comparable with bulk THz receivers in literature 68 . The multi-faceted 1NW receiver presents a smooth spectrum in the frequency domain, owing to its direct sampling nature.…”

THz Generation from the Topological Nodal Line Semimetal Co2MnGa

“…THz emitted radiation is focused on a ZnTe nonlinear crystal and detected by an electro-optical process. 45 Figure 1c shows the THz field emitted by the three films with different thicknesses, illuminated by a linearly S-polarized optical pulse with a fluence of 1.77 mJ/cm 2 . The terahertz intensity (from the 80 nm film) is ∼3% of that measured using a 500 μm thick ZnTe crystal under identical conditions (same exciting laser, illuminated area, and fluence).…”

“…The sharp dips between 1 and 3 THz are associated with water absorption from the atmospheric air. Due to the limitation of the ZnTe detection band, the THz signal emitted from the 80 nm film was also measured through a GaP crystal that was able to detect the higher THz frequencies although it was less sensitive to the field intensity due to the lower electro-optic coefficient . Even in this case, the emitted spectrum shows a cutoff at nearly 3 THz, suggesting that the whole CMG THz emitted spectrum is confined below this frequency.…”

“…A femtosecond pulse, centered at 800 nm and provided by a Coherent Legend amplifier (7 mJ of pulse energy, 35 fs of pulse duration, and 1 kHz of repetition rate), was used to illuminate the thin films in a reflection geometry at a 45° angle of incidence. THz emitted radiation is focused on a ZnTe nonlinear crystal and detected by an electro-optical process …”

Исследование Пропускания Легированного Железом Селенида Цинка В Терагерцовом Диапазоне Частот-=sup=-*-=/Sup=-

“…В предыдущих работах авторов [9,10] рассматривалась возможность поиска оптимальных значений интенсив-ности используемого лазерного излучения для электро-оптического преобразования в кристаллах ZnTe, ZnSe и GaP. С одной стороны, использование более мощных источников накачки может увеличить эффективность преобразования и создания высокоинтенсивных источни-ков ТГц излучения для большей глубины проникновения в образцы при спектроскопических исследованиях [11], а также для большей дальности передачи сигналов в системах беспроводной коммуникации [12].…”