Relativistic, single-cycle tunable-infrared pulses generated by a tailored plasma density structure

TL;DR

This paper introduces a novel method for generating tunable, relativistically intense, single-cycle infrared pulses in the 5-14μm range using a tailored plasma density structure, enabling advanced applications in strong-field physics.

Contribution

A new scheme utilizing plasma density tailoring for efficient, tunable, single-cycle IR pulse generation with phase locking to the drive laser.

Findings

Achieved 1.7% conversion efficiency in IR pulse generation.

Generated pulses tunable from 5 to 14 μm.

Carrier-envelope phase locked to the drive laser.

Abstract

The availability of intense, ultrashort coherent radiation sources in the infrared region of the spectrum is enabling the generation of attosecond X-ray pulses via high harmonic generation, pump-probe experiments in the "molecular fingerprint" region and opening up the area of relativistic-infrared nonlinear optics of plasmas. These applications would benefit from multi-millijoule single-cycle pulses in the mid to long wavelength infrared (LW-IR) region. Here we present a new scheme capable of producing tunable relativistically intense, single-cycle infrared pulses from 5-14$\mu$m with a 1.7% conversion efficiency based on a photon frequency downshifting scheme that uses a tailored plasma density structure. The carrier-envelope phase (CEP) of the LW-IR pulse is locked to that of the drive laser to within a few percent. Such a versatile tunable IR source may meet the demands of many cutting-edge applications in strong-field physics and greatly promote their development.