The Cavity Dumper is an acousto-optical switch placed inside the femtosecond laser resonator for intracavity operation. It reduces the pulse repetition rate of the modelocked laser system, while at the same time it increases the pulse energy by a factor of 4 approximately, which is a great benefit in comparison with standard pulse pickers placed outside the cavity that don't increase the pulse energy. The PulseSwitch reaches pulse energies of more than 40nJ (@500kHz, 800nm), a multiple of the pulse energies usually reached with CW modelocked Ti:S lasers. Pulse repetition rates can be selected between 200Hz to 9MHz. An external trigger offers the possibility of even lower repetition rates down to single shot.
The commercial APE PulseSwitch has been developed for the Coherent Mira. It works as it is in a perfect lab environment, with excellent temperature stability. It is not the case of our lab, and most probably of many labs in the world when long term laser power stability is an issue. Sometimes our measurements requires days of averaging and it is of primarily importance that the laser remains stable during acquisition. Because of this reason, we decided to fight un all the parts inside the APE PulseSwitch and to incorporate them into the MIRA cavity.