NUMERICAL AND EXPERIMENTAL INVESTIGATION ON ASE EFFECTS IN HIGH-POWERSLAB AMPLIFIERS

A three-dimensional calculation of the amplified spontaneous emission (ASE) is presented that allows rapid determination (with suitable appr oximation techniques) of the gain-length product (GLP) in high-power s lab amplifiers. These calculations include non-saturable absorption, A SE line-narrowing effects, and total internal reflections (TIR) at the pumping surfaces. A parametric study of the slab geometry is presente d and compared with experimental results. A good qualitative agreement between theory and experiment is achieved.