Amplifier Phase Stabilization
|Amplifier carrier wavelength||800 nm|
|Energy fluctuations||<1% (pulse-to-pulse, rms)|
|Repetition frequency||1…10 kHz|
|Input energy||>10 µJ/Pulse|
|Pulse length||<50 fs|
|Beam diameter||5-15 mm|
During amplification of phase stabilized femtosecond pulses, slow carrier-envelope phase drifts occur. The Menlo Systems APS800 is used to monitor and stabilize this phase relation after the amplifier. The APS800 expands full phase control to the regime of high power optical pulses used in todays most demanding experiments of attophysics and related areas.
To monitor the slow carrier-envelope phase drifts, a small part of the amplifier output is split off and spectrally broadened in a sapphire plate. In an optical interferometer, the green part of the resulting octave spanning spectrum is overlapped with the frequency doubled infrared part. With the help of a spectrometer and control software algorithms, the resulting interferogram is analyzed, and a slow correction signal is generated. This signal is fed into the corresponding input port of the phase stabilization electronics XPS800 or similar control electronic setups.