Abstract

Amplification by Innoslab amplifiers has been applied to ultrafast laser pulses for many years [1]. Recent progress in high power laser diodes and a new pumping scheme [2] made application of ytterbium doped laser crystals which support subpicosecond pulse durations possible. An Innoslab amplifier consists of a thin slab crystal (~10×10×1 mm³), which is cooled on the large faces (10×10 mm²) of the slab. The pump radiation is focused in a thin line propagating longitudinally through the slab, i.e. in direction of the amplified laser beam. The cavity around the slab reproduces the beam parameters of the seed beam each roundtrip in combination with a (cylindrical) thermal lens in one direction. In the other direction the slab crystal does not show thermal lens effects and the beam expands by a constant magnification M each roundtrip.

© 2009 IEEE