A Photoelectric Synergistically Excited Cold-Cathode High-Frequency Radiation Source: From GHz to THz

High-frequency radiation source devices based on vacuum electronics hold significant application value in high-speed wireless communication and high-resolution radar imaging. Herein, we propose a photoelectric synergistic excitation of cold cathode for high-frequency radiation source device scheme, which can generate electromagnetic waves in the GHz-to-THz frequency range without the need for complex electron beam modulation components or additional microwave feed sources. In this study, based on a carbon nanotube (CNT) cold-cathode electron gun, we designed and successfully implemented a radiation source device capable of producing 12.2-GHz electromagnetic wave output under the coexcitation of picosecond laser pulses and a static electric field, achieving a peak output power of $22.7~\boldsymbol {\mu } $ W. Based on the strategy, a radiation source device for 1 THz has been designed, which provides an option for the development of novel high-performance miniaturized terahertz radiation sources.