Intracavity ionization and pulse formation in femtosecond enhancement cavities.

We experimentally and numerically investigate the intracavity ionization of a dilute gas target by an ultrashort pulse inside a femtosecond enhancement cavity. Numerical simulations detail how the dynamic ionization of the gas target limits the achievable peak intensity of the evolving intracavity pulse beyond that of linear cavity losses, setting a constraint on the strength of the nonlinear interaction that can be sustained in such optical cavities. Experimental measurements combined with numerical simulations predict ionization levels in a femtosecond enhancement cavity for the first time. We demonstrate how the resonant response of the femtosecond enhancement cavity can itself be used as a sensitive probe of optical nonlinearities at high intensities.

[1]  Jun Ye,et al.  Femtosecond pulse amplification by coherent addition in a passive optical cavity. , 2002, Optics letters.

[2]  Ingmar Hartl,et al.  80 W, 120 fs Yb-fiber frequency comb. , 2010, Optics letters.

[3]  Jun Ye,et al.  Phase-coherent frequency combs in the vacuum ultraviolet via high-harmonic generation inside a femtosecond enhancement cavity. , 2005, Physical review letters.

[4]  Tino Eidam,et al.  Power scaling of a high-repetition-rate enhancement cavity. , 2010, Optics letters.

[5]  Jun Ye,et al.  Efficient output coupling of intracavity high-harmonic generation. , 2008, Optics letters.

[6]  Jun Ye,et al.  Nonlinear dynamics inside femtosecond enhancement cavities. , 2005, Optics express.

[7]  Jun Ye,et al.  High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity. , 2004, Optics letters.

[8]  van de Sanden MC,et al.  Recombination of argon in an expanding plasma jet. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[9]  V Pervak,et al.  High harmonic frequency combs for high resolution spectroscopy. , 2008, Physical review letters.

[10]  Eli Yablonovitch,et al.  Self-phase modulation and short-pulse generation from laser-breakdown plasmas , 1974 .

[11]  R. Jones,et al.  Generation of high-power frequency combs from injection-locked femtosecond amplification cavities. , 2008, Optics letters.

[12]  Thomas Udem,et al.  A frequency comb in the extreme ultraviolet , 2005, Nature.