Abstract-Threshold Conditions for Terahertz Laser Discharge in Atmospheric Gases

V. V. Kubarev, Ya. V. Getmanov, O. A. Shevchenko, P. V. Koshlyakov,

https://link.springer.com/article/10.1007%2Fs10762-017-0380-3

In this study, we accurately measured the breakdown thresholds in four atmospheric gases using the high-power terahertz radiation of the Novosibirsk free electron laser (NovoFEL). The breakdown intensities of the 130-μm radiation in a form of 74-ps pulses were equal to 1.1–1.4 GW/cm2. These data have been compared with calculations based on a phenomenological criterion for a breakdown and the classical theory of stochastic microwave heating of electrons. Presented are threshold conditions for a quasi-continuous plasma discharge that is maintained by means of a sequence of pulses of the NovoFEL. At a pulse repetition rate of 5.6 MHz, the discharge quenching thresholds are 15–60% lower than the breakdown thresholds depending on the amount of plasma emerging

Abstract-Radiation detectors based on PbSnTe:In films, sensitive in the terahertz range of the spectrum

• I. G. Neizvestnyi, 
• A. E. Klimov, 
• V. V. Kubarev, 
• V. N. Shumskii
• • 
    

http://link.springer.com/article/10.3103/S8756699016050083


This paper presents a review of studies of the photoelectric properties of PbSnTe:In films obtained by molecular beam epitaxy and photosensitive structures in the far infrared and submillimeter ranges based on these films. The parameters of photodetector arrays of this type and detectors based on doped semiconductors and superconductors are compared. One-dimensional (2×128 elements) and two-dimensional (128 × 128 elements) PbSnTe:In based arrays with a sensitivity threshold of ~22 μm and an operating temperature of T ≤ 16 K are implemented. Under background-free conditions, the noise equivalent power (NEP) was NEP ≤ 10−18 W/Hz0.5 at T = 7 K for a black body radiation source at TBB = 77 K. In the submillimeter range of the spectrum, sensitivity to laser radiation with a wavelength λ ≤ 205 μm and a value NEP ≤ 10−12 W/Hz0.5 was observed without optimization of the design of the photosensitive element and minimization of the measurement circuit noise. The directions of the development of PbSnTe:In based radiation detectors are considered..