Abstract
The gain and line-narrowing of the amplified spontaneous emissions (ASE) in apartially homogeneous high-gain Xe 3.51 μm laser amplifier were studied theoretically and experimentally with emphasis of saturation effect. The unidirectionally travelling ASE was generated by conveniently using optical isolators and used as a broadband radiation source. It has properties of 10μW/mm2 in intensity with fluctuation of less than 1% in 5hours, 43. 5MHz of the linewidth and 1, 0×10-3 radians of beam diverg-nce. The measured saturation intensity was 4.85μW/mm2 and a small signal gain was0.1cm-1. The theoretical prediction of the line-narrowing shows reasonablly good agreement with the measured one.
