Few-cycle optical pulse production from collimated femtosecond laser beam filamentation (original) (raw)

2010, Journal of the Optical Society of America B

A scheme for stable shot-to-shot few-cycle pulse production has been realized by launching an initially collimated laser beam into a gas tube. We found that the optimum parameters for the sevenfold compression of 55 fs, 5 mJ, Ti:Sapphire laser pulses are the following: 0.8-0.9 atm argon gas pressure and the registration aperture with a diameter of 300-700 m. A technique for the efficient extraction of the self-compressed pulse from the desired position along the filament has been provided by moving the registration aperture along the tube. With this technique, pulses as short as 8 fs were detected at a distance of 1 m from the filament starting position, in agreement with numerical simulations performed using a 3D + time axially symmetric code.