Theoretical and Experimental Studies on Novel High-Gain Seeded Free-Electron Laser Schemes

This dissertation focuses on the study of novel high-gain free-electron laser (FEL) operation schemes with external seed lasers. Several novel FEL schemes are proposed for the generation of intense coherent FEL pulses with short wavelength, sub-femtosecond pulse length or multiple carrier frequency properties, which meet the needs of FEL users.