Dephasingless two-color terahertz generation

Fuente: arXiv
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Bibliographic Details
Main Authors: Simpson, Tanner T., Pigeon, Jeremy J., Miller, Kyle G., Ramsey, Dillon, Froula, Dustin H., Palastro, John P.
Format: Preprint
Published: 2024
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_version_ 1866909219120218112
author Simpson, Tanner T.
Pigeon, Jeremy J.
Miller, Kyle G.
Ramsey, Dillon
Froula, Dustin H.
Palastro, John P.
author_facet Simpson, Tanner T.
Pigeon, Jeremy J.
Miller, Kyle G.
Ramsey, Dillon
Froula, Dustin H.
Palastro, John P.
contents A laser pulse composed of a fundamental and an appropriately phased second harmonic can drive a time-dependent current of photoionized electrons that generates broadband THz radiation. Over the propagation distances relevant to many experiments, dispersion causes the relative phase between the harmonics to evolve. This "dephasing" slows the accumulation of THz energy and results in a multi-cycle THz pulse with significant angular dispersion. Here, we introduce a novel optical configuration that compensates the relative phase evolution, allowing for the formation of a half-cycle THz pulse with almost no angular dispersion. The configuration uses the spherical aberration of an axilens to map a prescribed radial phase variation in the near field to a desired longitudinal phase variation in the far field. Simulations that combine this configuration with an ultrashort flying focus demonstrate the formation of a half-cycle THz pulse with a controlled emission angle and 1/4 the angular divergence of the multi-cycle pulse created by a conventional optical configuration.
format Preprint
id arxiv_https___arxiv_org_abs_2406_04613
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dephasingless two-color terahertz generation
Simpson, Tanner T.
Pigeon, Jeremy J.
Miller, Kyle G.
Ramsey, Dillon
Froula, Dustin H.
Palastro, John P.
Optics
Plasma Physics
A laser pulse composed of a fundamental and an appropriately phased second harmonic can drive a time-dependent current of photoionized electrons that generates broadband THz radiation. Over the propagation distances relevant to many experiments, dispersion causes the relative phase between the harmonics to evolve. This "dephasing" slows the accumulation of THz energy and results in a multi-cycle THz pulse with significant angular dispersion. Here, we introduce a novel optical configuration that compensates the relative phase evolution, allowing for the formation of a half-cycle THz pulse with almost no angular dispersion. The configuration uses the spherical aberration of an axilens to map a prescribed radial phase variation in the near field to a desired longitudinal phase variation in the far field. Simulations that combine this configuration with an ultrashort flying focus demonstrate the formation of a half-cycle THz pulse with a controlled emission angle and 1/4 the angular divergence of the multi-cycle pulse created by a conventional optical configuration.
title Dephasingless two-color terahertz generation
topic Optics
Plasma Physics
url https://arxiv.org/abs/2406.04613