# Two-color phase-of-the-phase spectroscopy in the multiphoton regime

## TL;DR

This paper investigates momentum-resolved photoelectron emission from xenon in two-color laser fields, using phase-of-the-phase spectroscopy to analyze phase dependence and reveal characteristic patterns in the multiphoton ionization regime.

## Contribution

It introduces the application of phase-of-the-phase spectroscopy to xenon ionization in two-color fields, providing analytical descriptions within the strong-field approximation.

## Key findings

- Characteristic checkerboard pattern in phase-of-the-phase spectra
- Analytical description within the strong-field approximation
- Experimental and theoretical agreement on phase dependence

## Abstract

Momentum-resolved photoelectron emission from xenon in colinearly polarized two-color laser fields at above-threshold ionization conditions is studied both experimentally and theoretically. We utilize phase-of-the-phase spectroscopy as recently introduced by Skruszewicz et al., Phys. Rev. Lett. 115, 043001 (2015) to analyze the dependence of the yields on the relative phase $\varphi$ between the fundamental and second harmonic laser fields. The resulting phase-of-phase spectra feature a characteristic checkerboard pattern, which can analytically be described within the strong-field approximation.