Recently, Zhang Zhelin and Chen Yanping, special associate researcher, Chen Min, and Prof. Sheng Zhengming of the Key Laboratory of Laser Plasma and Ministry of Education / IFSA Collaborative Innovation Center of Shanghai Jiaotong University made use of our laboratory KHz laser pointers device, In a controlled intense terahertz radiation.

Terahertz (THz) wave is located between the infrared and microwave electromagnetic radiation, is between the optical and electronics has not been widely developed band, it is in the terahertz remote sensing imaging, terahertz time-domain spectroscopy, terahertz Linear science and high-energy laser interaction with the diagnosis of substances has a great value. The strong terahertz radiation source can avoid the problem that the terahertz wave is absorbed by the water molecule when it is transported in the air, which has been paid more and more attention in recent years, because of the broadband generated by the two - color burning laser pointer field in plasma. The microscopic physical mechanism is mainly described by the ionization current model and the nonlinear four-wave mixing model. Previous studies have shown that this terahertz radiation source is a single-cycle broadband pulse. The precise manipulation of the parameters of the radiation pulse, including the radiation angle distribution, the carrier envelope phase, the pulse energy, and so on, is of great importance to its wide application.

By using the kilohertz laser device, the research team successfully realized the control of the single-period terahertz pulse of the radiation by controlling the length of the plasmonic fiber excited in the air and the relative phase difference of the pumped two-color high power laser pointer. Envelope phase, spatial distribution and peak intensity. Theoretically, a "linear dipole array" macroscopic model is proposed in which each part of the long filament is regarded as an independent terahertz radiation source. The far-field detected terahertz signal is the radiation of these point source arrays Coherent superposition, which is the key to explaining the generation of terahertz radiation under long-ray filament. The model well explains experimental observations and provides the basis for the generation of controllable terahertz radiation.