Fig. 1.

Schematic diagram of the irradiation device. The exposure of E. coli DH5α (pUC-rfp) to terahertz radiation was carried out using a terahertz free electron laser device (CTFEL). The frequency was 3.1 THz, the spot diameter was 1 cm and the average power was 33mW/cm². Terahertz radiation was released from the output hole coupled with the mirror downstream of the laser resonator, and then transmitted to the bunching collection system through the isolated vacuum environment. After bunching, terahertz radiation entered the atmospheric environment through the Mylar output window. The CTFEL radiation through each module was eventually directed with a rotary focus mirror to the sample in an incubator at 37 °C. The bacteria were exposed to continuous irradiation for 8 hours.