Instantaneous Multiphoton Ionization Rate and Initial Distribution of Electron Momenta

TL;DR

This paper generalizes the Yudin-Ivanov formula to provide a comprehensive analytical expression for single-electron spectra in strong field ionization, accounting for the instantaneous laser phase without momentum assumptions.

Contribution

It introduces a fully general analytical formula for electron spectra in strong fields, extending previous models by including laser phase dependence and removing momentum constraints.

Findings

Derived a universal formula for electron spectra in strong fields.

Revealed the influence of laser phase on ionization rates.

Unified previous approximations as special cases.

Abstract

The Yudin-Ivanov formula [Phys. Rev. A 64, 013409 (2001)] is generalized such that the most general analytical expression for single-electron spectra, which includes the dependence on the instantaneous laser phase, is obtained within the strong field approximation. No assumptions on the momentum of the electron are made. Previously known formulas for single-electron spectra can be obtained as approximations to the general formula.