Abstract

Kerr lens mode-locked Ti:sapphire lasers are capable of ultra short pulse and continuum generation, and, therefore, have enabled many novel experiments in nonlinear optics, optical coherence tomography and frequency metrology [1,2,3] over the last years. The key issue in sub-10 fs laser systems is the precise compensation of the optical dispersion caused by the laser crystal and the air residing within the laser cavity. Therefore, dispersion compensating laser optics, i.e. various forms of chirped mirrors and multi-GTI-mirrors have been developed [4,5,6]. To date, extremely stable, all mirror-dispersion controlled Ti:sapphire lasers emitting 8 fs pulses with spectra extending over 105 nm full width at half-maximum (FWHM) have been demonstrated [7]. Additional use of prism pairs for dispersion compensation results in an increased flexibility in the mirror design and therefore, in pulses as short as 5 fs with octave spanning spectra directly from the laser [8,9]. Recently, it has been found, that the fluctuations in the intracavity beam-pointing angle translates into undesired dispersion fluctuations in lasers with prisms, which is detrimental in experiments concerned with carrier-envelope phase stabilization. In this paper, we present an all mirror-dispersion controlled Ti:sapphire laser, which generates sub-8fs pulses and most notably, emits over a spectral width as large as 250 nm (FWHM) and even generates significant spectrum over 400 nm on a logarithmic scale suitable for carrier-envelope phase stabilization based on interference of second and third harmonic light [3]. Due to the reduced intracavity-losses, an optical to optical efficiency of more than 10% in the mode-locked state is achieved allowing for pump-powers below 3 W with a total output power of typically 300 mW.

© 2002 Optical Society of America