| It plays a key technical problem in the progress of terahertz technology to develop terahertz source with high radiant energy,micro terahertz source.GaAs photoconductive antenna as a terahertz radiation source is currently widely used to produce terahertz wave methods.Now,all of the GaAs photoconductive switches are used in linear mode with a low radiant energy.when the GaAs photoconductive switch operates in an avalanche multiplication mode,the power capacity of output ultrafast electric pulse is much higher than that in a linear mode,which in theory can greatly improve the radiation intensity of the electromagnetic wave.To develop GaAs photoconductive antenna with the avalanche multiplication mechanism for generating the high intensity THz emission,the work as follows:In the linear mode,the effects of the laser,the current limiting resistor,the energy storage capacitor,the power supply,the trigger spot and the bias voltage on the transmission efficiency of the repetitive frequency laser triggered photoconductive switch test circuit was investigated.The microscopic process of quenching of the photoconductive switch in the nonlinear mode was given.The kilohertz nonlinear quenching output the average pulse width of about 1.4ns is achieved using the capacitor residual voltage method.The terahertz electromagnetic time domain waveform and electrical pulses output by the GaAs photoconductive antenna gaps of 0.817 mm is tested by the classical terahertz time domain spectroscopy system.In order to test the kilohertz avalanche multiplication terahertz waveform to construct the kilohertz terahertz time domain spectroscopy system. |
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