Carrier-envelope phase stable few-cycle pulses at 400 kHz for electron-ion coincidence experiments

Abstract

Coincident electron-ion detection after photoionization in a "reaction microscope" is a very powerful tool to study atomic and molecular dynamics. However, the implementation of this tool in the field of attosecond science has so far been rather limited, due to the lack of high repetition rate laser sources capable of delivering few-cycle pulses with sufficient energy per pulse. In this article, the development of a Non-collinear Optical Parametric Amplifier (NOPA) capable of delivering Carrier-Envelope Phase (CEP) stable pulses with sub-6 fs duration and pulse energies in the few-µJ range is presented. The potential of combining the high repetition rate source and a reaction microscope operating at this high frequency is demonstrated in a proof-of-principle experiment on strong field ionization of Ar atoms.

Carrier-envelope phase dependent high-order harmonic generation with a high-repetition rate OPCPA-system

“…Many applications in attosecond science should benefit from attosecond sources operating at higher repetition rates, i.e. in the MHz range [22,[28][29][30][31][32]. Examples of such applications are coincidence detection of two or more particles, which require a low number of events per laser shot [33], but a large number of events per second to build up statistics, photoelectron spectroscopy and microscopy in solids and on solid surfaces [34,35] where space charge effects can be a serious obstacle.…”

High Average Power Near‐Infrared Few‐Cycle Lasers

“…is identified as resonantly enhanced ionization through intermediate Rydberg states, whereas the reasons for the huge number of minima for a.u. is not yet clear …”

“…Few‐cycle pulses delivered by a 400 kHz repetition rate OPCPA system have been utilized for strong‐field ionization of argon. For this purpose, the 6 fs pulse has been focused to ∼ 7 × 10 13 W/cm² peak intensity.…”

“…N(p║,p┴) is proportional to |ψ(p║,p┴)|2 p┴ where ψ(p║,p┴) is the wavefunction of the outgoing electron. Reproduced from …”

Attosecond Dynamics in Atoms

“…However, with attosecond experiments addressing increasingly complex systems, the needs for the implementation of such coincident detection schemes has grown substantially in the last few years. Using OPCPA, the development of CEP-stable, high repetition rate, few-cycle drivers that are developed for attosecond science has already been reported and we may anticipate the first pump-probe experiments on attosecond time scales soon [37,38].…”