Laser and Particle Beams

High-power Ti:Sapphire lasers: Temporal contrast and spectral narrowing

Kalashnikov a1c1 , Osvay a1a2 and Sandner a1
a1 Max Born Institute for Nonlinear Optics and Ultrafast Spectroscopy, Berlin, Germany
a2 Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary

Article author query
kalashnikov m   [Google Scholar] 
osvay k   [Google Scholar] 
sandner w   [Google Scholar] 


New extensions of the chirped pulse amplification (CPA) scheme designed specially for petawatt Ti:Sapphire lasers are considered. The two new schemes support a spectral bandwidth sufficient for 20 fs pulses and a temporal contrast of 1012. The Double CPA scheme consists of two CPA stages with an intermediate temporal pulse filtering for temporal contrast improvement. The scheme of Negative–Positive CPA amplification takes advantage of consecutive saturated amplification of down chirped and up chirped pulses. This allows a suppress imprint of gain narrowing, which usually limits the spectral bandwidth at the multi-terawatt power level, and reach the bandwidth in excess of 50 nm without using any direct spectral shaping of the pulse.

(Received November 5 2006)
(Accepted January 31 2007)

Key Words: High power lasers; Saturation; Spectral narrowing; Temporal contrast.

c1 Address correspondence and reprint requests to: M. Kalashnikov, Max Born Institute for Nonlinear Optics and Ultrafast Spectroscopy, Max-Born-Strasse 2/A, Berlin 12489, Germany. E-mail: