Compression of long-cavity Ti:Sapphire oscillator pulses with large-mode-area photonic crystal fibers

摘要

With the advent of long-cavity, chirped-pulse Ti:sapphire lasers, high repetition rate oscillator pulses with hundreds of nJ energy and tens of fs pulse duration became available [1]. Conventional extracavity compression schemes are not suitable for this pulse energy range due to either the damage threshold of single-mode fibers or the low level of nonlinearity in gaseous media filling hollow-core fibers. In order to overcome these limitations, here we demonstrate a femtosecond pulse compression scheme employing large mode area (LMA) photonic crystal fibers (PCF) to compress the 190-nJ, 75-fs output pulses of a chirped pulse Ti:sapphire oscillator to 18-fs, 100-nJ pulses in a single stage. The left panel of Fig. 1 depicts the experimental setup. Firstly, 2-ps chirped pulses from a long-cavity, chirped pulse Ti:sapphire oscillator were compressed close to their transform limit with a 4-prism compressor resulting in 75-fs pulses.