Abstract
In this paper, we report our study on a burst-mode GHz/THz pulse train photoinjector operating at room temperature. For the GHz operation mode, we illuminate the photocathode by a self-developed driver laser to generate tens of electron pulses at 2.856 GHz in an adjustable 5-10 ns temporal envelope repeating at 100 MHz. For the THz operation mode, we propose the use of a spatially modulated driver laser at the photocathode to generate an electron-pulse train with a bunching frequency in the THz-PHz range.