Study On Frequency Upconversion Detection Of THz Wavess Using Glow Discarge Gas

With the development of ultra-fast optoelectronic technology,terahertz research has made revolutionary progress.At present,THz waves have been applied in wireless communication,detection and imaging.However,THz detection technology is still a major obstacle to the development of THz technology.Most of the current THz detectors are expensive and need to work at lower temperatures,and are not suitable for widespread use in practical applications.To this problem,we proposed to use the glow discharge gas to detect THz waves by frequency up-conversion method,developed a frequency up-conversion detector,and initially tested its performance,proved that it is a low-cost and room-temperature operation high sensitivity terahertz detector.This paper further proposes to study the detection performance and mechanism of the frequency upconversion detector by studying the influence of THz wave on the spectrum of neon lamp,and qualitatively analyzes the detection mechanism of the frequency upconversion detector from the perspective of quantum mechanics.And the results obtained are as follows:Firstly,the volt-ampere characteristic curve of the neon lamp used in the experiment was measured.By analyzing the volt-ampere characteristic curve,it was determined that the discharge state of the neon lamp used in the normal glow discharge state and the abnormal glow discharge state was stable,it suitable for experiments.Secondly,the frequency up-conversion detector was tested by experiments,and the luminescence spectrum of the neon lamp with or without the THz radiation was collected by using the spectrometer.After the analysis,it is found that under the influence of THz radiation,the luminous intensity of the neon lamp is obviously enhanced in some frequency bands.Thirdly,the mechanism of the frequency up-conversion method of THz wave by glow discharge gas is further studied.The reason of the enhancement of the luminescence intensity of neon lamp is qualitatively explained by the theory of quantum mechanics.It is proposed that the highly-excited state atom plays a key role in the interaction between plasma and THz photons.It is considered that there are a small number of highly excited erbium atoms in the plasma discharge space.Highly-excited state atoms can be ionized by absorbing a THz photon due to the electrons at the very high energy level.The newly ionized electrons are accelerated at the cathode after the electric field is accelerated.The dark region triggers further electron avalanche effects,which directly leads to more electrons entering the negative glow region,resulting in a significant increase in plasma luminescence.