Raman free electron laser oscillator

A free electron laser oscillator with distributed feedback cavity (DFC) is developed. The theories and experiments of the Raman free electron laser (400 KeV/800 A) with DFC are studied. The spectral measurements using a microwave grating spectrometer are presented. The narrowed spectral bandwidth covered range of 8.6 mm approx.8.9 mm with central wavelength at 8 mm and output power enhancement show that oscillation happened.