Femtosecond chirp-variable apparatus using a chirped mirror pair for quantum coherent control

We demonstrate a femtosecond chirp-variable apparatus with a chirped mirror pair to manipulate the chirp rate of pulses precisely. The apparatus is simple, easy-to-use, and compact with high energy durability and low insertion loss. Negative chirp can be added to the pulse digitally without a deviation of the output optical axis, which gives the group velocity dispersion of -41 fs(2) at each reflection on the chirped mirror. The whole apparatus dimension is 180 mm x 76 mm. The reflectively and damage threshold of the chirped mirror are 99.5% and 0.6 J/cm(2), respectively. Using this chirp-variable apparatus, a chirp-dependent fluorescence in cyanine dye molecules (IR-140) is observed. The apparatus opens a new possibility to manipulate optical phase information. (C) 2004 Elsevier B.V. All rights reserved.