We report the implementation and operation of novel superhigh-reflectivity negative-dispersion dielectric mirrors for use in tunable ultrafast laser systems. The mirror structure is divided into two distinct regions: an underlying superhigh-reflectivity dielectric quarter-wavelength stack and an overlying negative-dispersion section consisting of only a few layers and forming simple multiple Gires–Tournois interferometers. The example that we present was designed for operation from 800 to 900 nm and has a near-constant group-delay dispersion of -40 fs<sup>2</sup> and a peak reflectivity greater than 99.99%. We show a comparison of the predicted and the measured mirror performance and application of these mirrors in a mode-locked Ti:sapphire laser tunable from 805 to 915 nm.
© 2000 Optical Society of America
(140.4050) Lasers and laser optics : Mode-locked lasers
(310.1620) Thin films : Interference coatings
(320.5540) Ultrafast optics : Pulse shaping
(320.7090) Ultrafast optics : Ultrafast lasers
(320.7160) Ultrafast optics : Ultrafast technology
B. Golubovic, R. R. Austin, M. K. Steiner-Shepard, M. K. Reed, Scott A. Diddams, D. J. Jones, and Amelia G. Van Engen, "Double Gires—Tournois interferometer negative-dispersion mirrors for use in tunable mode-locked lasers," Opt. Lett. 25, 275-277 (2000)