Effect of amplified spontaneous emission in Heaven Ｉ preamplifier

In the numerical simulation of 3D amplified spontaneous emission(ASE), we have investigated the effects of side reflection of ASE and the spectrum line shapes (Gaussian, Lorentzion and Square hat forms) of KrF spontaneous emission, including the influence of space grids in calculation. The ranges that ASE can affect the amplification quality of the Heaven 1 preamplifier are gotten. We have found that the ASE effects of square hat pulse can be twice of that of Lorentzion pulse, and the extraction efficiency will be decreased about 40%. From our calculation, we learn that the efficiency can decline to about 35% if we include the influence of ASE with square hat pulse and reflection coefficient of 0.2, in contrasting with the situation which not considering the ASE effects.