# High harmonic generation spectroscopy via orbital angular momentum

## TL;DR

This paper introduces a novel high harmonic generation spectroscopy method using orbital angular momentum in laser fields, enabling detailed phase and amplitude analysis of HHG in diatomic nitrogen.

## Contribution

It demonstrates the use of orbital angular momentum in laser fields to improve HHG spectroscopy and interferometry techniques.

## Key findings

- Successful generation of tightly spaced laser foci with different OAM
- Effective measurement of HHG phase and amplitude in nitrogen
- Validation of OAM-based HHG interferometry quality

## Abstract

We present an experimental technique using orbital angular momentum (OAM) in a fundamental laser field to drive High Harmonic Generation (HHG). The mixing of beams with different OAM allows to generate two laser foci tightly spaced to study the phase and amplitude of HHG produced in diatomic nitrogen. Nitrogen is used as a well studied system to show the quality of OAM based HHG interferometry.