Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Time-frequency representations of high order harmonics

Open Access Open Access

Abstract

We calculate time-frequency representations (TFRs) of high-order short pulse harmonics generated in the interaction between neon atoms and an intense laser field, including macroscopic effects of propagation and phase matching in the non-linear medium. The phase structure of the harmonics is often complicated and the TFR can help to resolve the different components of this structure. The harmonic pulses exhibit an overall negative chirp, which can be attributed in part to the intensity dependence of the harmonic dipole phase. In some cases, the harmonic field separates in the time-frequency domain and clearly exhibits two different chirps. We also compute an experimental realization of a TFR (using Frequency Resolved Optical Gating, FROG) for a high harmonic. Due to the complicated time structure of the harmonics, the FROG trace is visually complex.

©2001 Optical Society of America

Full Article  |  PDF Article
More Like This
Frequency chirp of long electron quantum paths in high-order harmonic generation

E. Benedetti, J-P. Caumes, G. Sansone, S. Stagira, C. Vozzi, and M. Nisoli
Opt. Express 14(6) 2242-2249 (2006)

Pressure control of phase matching in high-order harmonic generation in hollow fibers filled with an absorbing weakly ionizing gas

A. N. Naumov, A. M. Zheltikov, A. B. Fedotov, D. A. Sidorov-Biryukov, A. P. Tarasevitch, Ping Zhou, and D. von der Linde
J. Opt. Soc. Am. B 18(6) 811-817 (2001)

Time-frequency analysis of high harmonic generation using a probe XUV pulse

T. S. Sarantseva, A. A. Silaev, A. A. Romanov, N. V. Vvedenskii, and M. V. Frolov
Opt. Express 29(2) 1428-1440 (2021)

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (5)

Fig. 1.
Fig. 1. Time-frequency representations of the 45th (left) and the 89th (right) harmonics emitted from a neon atom subject to a 216 fs laser pulse with a peak intensity of 6×1014 W/cm2.
Fig. 2.
Fig. 2. (a) TFR trace of the 45th harmonic in neon after propagation through a 1 mm long gas jet. In (b) we show the logarithm of the spectrogram shown in (a).
Fig. 3.
Fig. 3. Polarization gate FROG trace of the 45th harmonic shown in Fig. 2.
Fig. 4.
Fig. 4. Time profile of the 45th harmonic after propagation through the gas jet.
Fig. 5.
Fig. 5. The time-frequency behavior of the harmonic radiation found at (a) the outer edge of the farfield profile, and (b) on-axis in the farfield profile.

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

S ( ω , τ ) = E ( t ) W ( t τ ) e iωt d t 2 ,
S p ( ω , τ ) = 0 r d r E ( r , t ) W ( t τ ) e iωt d t 2 ,
β i α i I 0 π 2 2 T 2 .
Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved