Chirped pulse amplification (CPA) is a technique for amplifying an ultrashort laser pulse up to the petawatt level with the laser pulse being stretched out temporally and spectrally prior to amplification. CPA is the current state of the art technique which all of the highest power lasers (greater than about 100 terawatts, with the exception of the ~500 TW National Ignition Facility) in the world currently utilize. Some examples of these lasers are the Vulcan Petawatt Upgrade at the Rutherford Appleton Laboratory's central laser facility, the Diocles Laser at the University of Nebraska-Lincoln, the Gekko Petawatt laser at the Gekko XII facility in the Institute of Laser Engineering at Osaka University, the OMEGA EP laser at the University of Rochester's Lab for Laser Energetics and the now dismantled petawatt line on the former Nova laser at the Lawrence Livermore National Laboratory. Apart from these state-of-the-art research systems, a number of commercial manufacturers sell Ti:sapphire-based CPAs with peak powers of 10 to 100 gigawatts.