Abstract

In these several years, the pulse duration of a mode-locked Ti:sapphire oscillator has been reduced. It is a chirped mirror¹⁾, that contributes very much to the shortening, because a chirped mirror can compensate the high order dispersions with wide spectral range (Δλ> 300 nm) in the cavity of the oscillator. For recent sub-6 fs pulse generation²⁾ from a mode-locked oscillator, a double-chirped mirror was used. A double-chirped mirror has very thin (~10 nm) layers. It is difficult to fabricate it, because an ultimately precise control of thickness of the layers is required.

© 2000 IEEE