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Related papers: Directional THz generation in hot Rb vapor excited…

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Using a 3D fully-vectorial nonlinear time-domain analysis we numerically investigate the generation of terahertz radiation by pumping a photonic crystal microcavity out of resonance. High quality factors and a quadratic susceptibility lead…

Optics · Physics 2009-11-11 Andrea Di Falco , Claudio Conti , Gaetano Assanto

Two-color laser induced plasma filamentation in air could serve as tabletop sources of broadband terahertz (THz) pulses. Ubiquitous air in the earth facilitates its widespread utilities, particularly, in wireless communication and remote…

The experimental device for generation of undulator radiation in terahertz wavelength region by use of undulator on ferromagnets is created. The device is based on a beam of a microtrone with the energy 7.5 MeV. The radiation wavelength is…

Based on spatial-temporal symmetry breaking mechanism, we propose a novel scheme for terahertz (THz) wave generation from hyper-Raman lines associated with the 0th harmonic (a particular even harmonic) in a two-level quantum system driven…

Optics · Physics 2015-06-03 Wei Zhang , Shi-Fang Guo , Su-Qing Duan , Xian-Geng Zhao

We develop the microscopic theory of a terahertz (THz) laser based on the effects of resonant tunneling in a double quantum well heterostructure embedded in both optical and THz cavities. In the strong coupling regime the system hosts…

Mesoscale and Nanoscale Physics · Physics 2014-02-26 K. Kristinsson , O. Kyriienko , I. A. Shelykh

We study telecom-wavelength spectra of a Rydberg state in an atomic vapor with a three-photon excitation scheme. Two lasers of 780 nm and 776 nm are used to pump Rubidium-85 atoms in a vapor cell to the $5D_{\mathrm{5/2}}$ state, from which…

Atomic Physics · Physics 2022-09-20 Wenfang Li , Jinjin Du , Mark Lam , Wenhui Li

We demonstrate record conversion efficiencies of up to 0.9 percent for narrowband (1 percent relative bandwidth) THz generation by strongly-cascaded difference frequency generation. These results are achieved using a novel laser source,…

Direct laser electron acceleration in near-critical density plasma produces collimated electron beams with high charge $Q$ (up to $\mu$C). This regime could be of interest for high energy THz radiation generation, as many of the mechanisms…

Plasma Physics · Physics 2023-10-31 D A Gorlova , I N Tsymbalov , I P Tsygvintsev , A B Savelev

We experimentally investigate the limits to 800 nm-to-terahertz (THz) energy conversion in lithium niobate at room temperature driven by amplified Ti:Sapphire laser pulses with tilted-pulse-front. The influence of the pump central…

We report the synthesis of arbitrary optical waveforms by manipulating the spectral phases of Raman sidebands with a wide frequency spacing line-by-line. Trains of rectangular and triangular pulses are stably produced at an ultrahigh…

Optics · Physics 2015-05-19 Kanaka Raju Pandiri , Masayuki Katsuragawa

We have shown that a coherently driven solid state medium can potentially produce strong controllable short pulses of THz radiation. The high efficiency of the technique is based on excitation of maximal THz coherence by applying resonant…

We have designed and fabricated a new type of terahertz (THz) emitter that radiates THz waves along the surface-normal direction because of the lateral distributions of the transient electric dipoles. The excitation and measurements were…

Optics · Physics 2015-06-11 Jong-Hyuk Yim , Hoonil Jeong , Jin-Dong Song , Young-Dahl Jho

The common approach for producing Rydberg atoms in warm vapor cells is with lasers arranged in a counter-propagating, collinear configuration. Doppler effects in these configurations reduce the efficiency of excitation to the Rydberg state…

Achieving efficient terahertz (THz) generation using compact turn-key sources operating at room temperature and modest power levels represents one of the critical challeges that must be overcome to realize truly practical applications based…

We show that planar semiconductor microcavities in the strong coupling regime can be used as sources of stimulated terahertz (THz) radiation. Emitted THz photons would have a frequency of the spliting of the cavity polariton modes. The…

Mesoscale and Nanoscale Physics · Physics 2010-11-23 K. V. Kavokin , M. A. Kaliteevski , R. A. Abram , A. V. Kavokin , S. Sharkova , I. A. Shelykh

The coherent radiation spectrum of two-level polar molecules with UV transition is studied at the multiphoton resonant excitation by a moderately strong laser field. The spectrum corresponding to harmonic generation and low-frequency…

Atomic Physics · Physics 2011-06-14 H. K. Avetissian , B. R. Avchyan , G. F. Mkrtchian

We study the influence of the polarization states of femtosecond two-color pulses ionizing gases on the emitted terahertz radiation. A local-current model and plane-wave evaluations justify the previously-reported impact on the THz energy…

The terahertz spectral regime, ranging from about 0.1 to 15 THz, is one of the least explored yet most technologically transformative spectral regions. One current challenge is to develop efficient and compact terahertz emitters/detectors…

Mesoscale and Nanoscale Physics · Physics 2019-03-12 Liang Luo , Ioannis Chatzakis , Jigang Wang , Fabian B. P. Niesler , Martin Wegener , Thomas Koschny , Costas M. Soukoulis

Utilizing two-photon excitation in hot Rb vapor we demonstrate the generation of collimated optical fields at 420 nm and 1324 nm. Input laser beams at 780 nm and 776 nm enter a heated Rb vapor cell collinear and circularly polarized,…

Atomic Physics · Physics 2015-06-17 J. F. Sell , M. A. Gearba , B. D. DePaola , R. J. Knize

Femtosecond laser filament generates strong terahertz (THz) pulse in air. In this paper, THz pulse waveform generated by femtosecond laser filament has been experimentally investigated as a function of the length of the filament.…

Optics · Physics 2013-10-22 Jiayu Zhao , Yizhu Zhang , Zhi Wang , Wei Chu , Bin Zeng , Ya Cheng , Zhizhan Xu , Weiwei Liu