English
Related papers

Related papers: Polychromatic forward-directed sub-Doppler emissio…

200 papers

Luminescence as a mechanism for terahertz emission from femtosecond laser-induced plasmas is studied. By using a fully microscopic theory, Coulomb scattering between electrons and ions is shown to lead to luminescence even for a spatially…

Plasma Physics · Physics 2009-11-10 W. Hoyer , J. V. Moloney , E. M. Wright , A. Knorr , M. Kira , S. W. Koch

We study modulation-free methods for producing sub-Doppler, dispersive line shapes for laser stabilization near the potassium D2 transitions at 767 nm. Polarization spectroscopy is performed and a comparison is made between the use of a…

Atomic Physics · Physics 2012-07-19 K. Pahwa , L. Mudarikwa , J. Goldwin

A way to considerably enhance terahertz radiation, emitted in the interaction of intense mid-infrared laser pulses with atomic gases, in both the total energy and the electric-field amplitude is suggested. The scheme is based on the…

Atomic Physics · Physics 2018-12-05 V. A. Tulsky , M. Baghery , U. Saalmann , S. V. Popruzhenko

We theoretically study the generation of terahertz (THz) radiation by two-color filamentation of ultrashort laser pulses with different wavelengths. We consider wavelengths in the range from 0.6 to 10.6 $\mu$m, thus covering the whole range…

Optics · Physics 2018-08-20 Vladimir Yu. Fedorov , Stelios Tzortzakis

Observations suggest that in normal period radio pulsars, coherent curvature radiation is excited within 10$\%$ of the light cylinder. The coherence is attributed to Langmuir mode instability in a relativistically streaming one-dimensional…

High Energy Astrophysical Phenomena · Physics 2022-08-15 Sk. Minhajur Rahaman , Dipanjan Mitra , George I. Melikidze

Unexpected spectral features are observed in the two photon spectrum of the pure water in the forward direction when an 80 femtosecond laser pulse is focused at 10^10Wcm-2 or less. Such intensity is much lower than the breakdown or…

Chemical Physics · Physics 2007-06-19 Hong-tao Bian , Yi Rao , Yan-yan Xu , An-an Liu , Yuan Guo , Hong-fei Wang

More than 4 orders of magnitude of cavity-linewidth narrowing in a rare-earth-ion-doped crystal cavity, emanating from strong intracavity dispersion caused by off-resonant interaction with dopant ions, is demonstrated. The dispersion…

Quantum Physics · Physics 2015-07-07 Mahmood Sabooni , Qian Li , Lars Rippe , R. Krishna Mohan , Stefan Kroll

Ultrashort pulsed lasers (USPL) can produce thin columns of plasma in air via femtosecond filamentation, and these plasmas have been found to generate broadband TeraHertz (THz) and Radio Frequency (RF) radiation. A recent theory argues that…

Plasma Physics · Physics 2024-12-10 Travis Garrett , Anna Janicek , J. Todd Fayard , Jennifer Elle

A solid-state organic thin-film laser with intracavity frequency doubling is reported. Tunable ultraviolet emission from 309 to 322 nm is achieved from a vertical external cavity surface-emitting organic laser, with 2 % efficiency (1 $\mu$J…

Infrared femtosecond laser pulses are important tools both in strong-field physics, driving X-ray high-harmonic generation, and as the basis for widely tuneable, if inefficient, ultrafast sources in the visible and ultraviolet. Although…

Optics · Physics 2020-10-14 Christian Brahms , Federico Belli , John C. Travers

We derive the analytical theory describing the process of sub-femtosecond pulse formation from a quasi-monochromatic seeding extreme ultraviolet (XUV) radiation, which propagates in active medium of a hydrogen-like plasma-based X-ray laser…

We report on experimental observation of electromagnetically induced transparency and slow-light (vg ~ c/607) in atomic sodium vapor, as a potential medium for a recently proposed experiment on slow-light enhanced relative rotation sensing…

Quantum Physics · Physics 2009-11-11 Renu Tripathi , G. S. Pati , M. Messall , K. Salit , M. S. Shahriar

A simple experiment is presented which indicates that electromagnetic fields propagate superluminally in the near-field next to an oscillating electric dipole source. A high frequency 437MHz, 2 watt sinusoidal electrical signal is…

General Physics · Physics 2007-05-23 William D. Walker

Vector beams with spatially structured polarization and intertwined spin-orbital angular momentum (SAM-OAM) provide powerful degrees of freedom for tailoring light-matter interactions. While such structured beams are well established in the…

The laser-plasma accelerator has attracted great interest for constituting an alternative in the production of the relativistic electron beams of high peak current. But the generated electron beam has poor monochrome and emittance, which…

Optics · Physics 2017-03-22 Zhinan Zeng , Ruxin Li , Zhizhan Xu

We theoretically investigate the spectral property of biphoton state from the cascade emissions from a Doppler-broadened atomic ensemble. This biphoton state is spontaneously created in the four-wave-mixing process. The upper transition of…

Quantum Physics · Physics 2019-06-14 T. H. Chang , G. -D. Lin , H. H. Jen

In the framework of linear optics, light fields do not interact with each other in a medium. Yet, when their field amplitude becomes comparable to the electron binding energies of matter, the nonlinear motion of these electrons emits new…

We demonstrate that phase-matched frequency upconversion of ultrafast laser light can be extended to shorter wavelengths by using longer driving laser wavelengths. Experimentally, we show that the phase-matching cutoff for harmonic…

A tapered semiconductor amplifier is injection seeded by a femtosecond optical frequency comb at 780 nm from a mode-locked Ti:sapphire laser. Energy gains over 17 dB (12 dB) are obtained for 1 mW (20 mW) of average input power when the…

Optics · Physics 2009-11-11 Flavio C. Cruz , Matthew C. Stowe , Jun Ye

Frequency comb-referenced measurements of sub-Doppler laser saturation dip absorption lines in the $v_1+v_3$ band of acetylene near $1.5\,\mu \mathrm{m}$ are reported. These measurements include transitions involving higher rotational…

Chemical Physics · Physics 2020-03-10 Sylvestre Twagirayezu , Gregory E. Hall , Trevor J. Sears