The MPA Ti: Sapphire multipass amplifier is designed to amplify single pulses from a CW mode-locked Ti: Sapphire laser. Typically an input pulse with energy of only a few nanojoules can be amplified to over 1mJ. This represents an overall amplification of greater than 106. The amplification takes place as the optical pulse passes through a Ti: Sapphire laser rod, which has been optically excited by a laser pulse from the Q-switch pump laser. We use a Brewster cut Ti: Sapphire laser rod with the high-resistant mirror on the back side (HR 490-550 nm and HR 740-860 nm). It allows us to use the pump energy most effectively and select the length of active medium for maximal gain.
