We have developed a useful method for power multiplication of KrF laser lig
ht, called forward Raman pulse compression. In this method, a multi-pass fo
rward Raman amplifier is used. Adjustment of incident timing between pump a
nd Stokes light into each path provides efficient Raman energy conversion f
rom long KrF laser to short pulse Stokes light. Even in the case of double
path configuration, output Stokes was demonstrated to grow up to 1.3 times
the pump intensity. By using an intersecting multi-path of Stokes and pump
light, spatial non-uniformity of the output Stokes reduced to less than 5%.
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