Demonstration of a tilted-pulse-front pumped plane-parallel slab terahertz source

Nugraha, Priyo S.; Krizsán, Gergő; Lombosi, Csaba; Pálfalvi, László; Tóth, György; Almási, Gábor; Fülöp, J. A.; Hebling, J.

doi:10.1364/ol.44.001023

Cited by 44 publications

(25 citation statements)

References 21 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, a modified hybrid approach was proposed to provide uniform interaction length across large pump and THz beams. [71] In this setup, the nonlinear medium is a plane-parallel LN slab with an echelon structure on its input surface ( Figure 11a). [71] In this setup, the nonlinear medium is a plane-parallel LN slab with an echelon structure on its input surface ( Figure 11a).…”

Section: Novel Scalable Conceptsmentioning

confidence: 99%

“…[70] A proof-of-principle experimental demonstration has also been carried out. [71,72] We note that a reflective echelon has Adv. Inside the LN slab, a segmented tilted pulse front is formed with an average tilt angle as required by phase matching.…”

Section: Novel Scalable Conceptsmentioning

confidence: 99%

“…Reproduced with permission [71]. Calculated THz-pulse waveforms at different positions across the THz beam for an b) LN prism and c) a plane-parallel LN slab.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Laser‐Driven Strong‐Field Terahertz Sources

Fülöp

Tzortzakis

Kampfrath

2019

Advanced Optical Materials

Self Cite

270

147

View full text Add to dashboard Cite

reason for this interest relies on the fact that THz radiation can couple resonantly to numerous fundamental motions of ions, electrons, and electron spins in all phases of matter. For example, in solids, the THz range overlaps with the frequency of lattice vibrations (phonons), the collision rates of conduction electrons, the binding energy of bound electron-hole pairs (excitons), and the precession frequency of spin waves (magnons). Consequently, THz radiation, both continuous-wave and pulsed, has been used for characterization of and gaining insight into elementary processes in complex materials. The majority of these studies used relatively weak THz fields and, thus, probed the linear response of the material, without inducing notable material modifications.Only recently, however, completely new avenues in THz science were opened up by triggering nonlinear THz responses of materials. [3][4][5][6][7][8][9][10][11][12][13] Instead of using weak fields to primarily observe selected THz modes such as phonons or magnons, strong fields allow one to actively drive them to unprecedentedly large amplitudes, potentially thereby resulting in novel states of matter. [6,8,11] For example, simulations suggest that exciting matter with intense THz transients may lead to massive modifications of electrically [14] or magnetically [15] ordered domains and enable the acceleration of free ions to ≈1 MeV, [16] and postacceleration to 50-100 MeV energies. [17] Remarkable experimental results such as switching of magnetic order, [18,19] parametric amplification of optical phonons, [20] novel insights into spin-lattice coupling, [21,22] and acceleration of free electrons in a THz linear accelerator [23] were achieved only recently. This progress has been made possible by the development of laser-driven table-top THz sources routinely providing pulses with unprecedented energies and peak electric and magnetic field strengths throughout the entire THz spectral range. Different laser-based THz pulse generation techniques can be used to access different parts of the spectral range extending from 0.1 to 10 THz. Some of the recently developed technologies enable the generation of radiation with even larger bandwidth or tuning range up to 100 THz and beyond, which lead to an extension of what is called the THz spectral range. An overview of the approximate spectral coverage and the achieved highest pulse energies and peak electric-field strengths of various laserdriven technologies is given in Figure 1. ScopeIn this work, the basic principles of femtosecond-laser-driven intense pulsed THz sources and their recent development are reviewed. These sources are capable of delivering peak electric field strengths on the MV cm −1 scale. Corresponding typical THz pulse energies are on the µJ-to-mJ level, depending on A review on the recent development of intense laser-driven terahertz (THz) sources is provided here. The technologies discussed include various types of sources based on optical rectification (OR), spintronic emitters, and laserfilame...

show abstract

Section: Novel Scalable Conceptsmentioning

confidence: 99%

Section: Novel Scalable Conceptsmentioning

confidence: 99%

See 1 more Smart Citation

Laser‐Driven Strong‐Field Terahertz Sources

Fülöp

Tzortzakis

Kampfrath

2019

Advanced Optical Materials

Self Cite

270

147

View full text Add to dashboard Cite

show abstract

“…However, the spectrum obtained from organic materials is typically centered in the 2 to 10 THz, while lower frequencies are more suitable for particle acceleration. the pump beam [16,17]. Although the slab-like structure allows significant energy scalability, imaging errors still remain a limiting factor.…”

Section: Introductionmentioning

confidence: 99%

Single-cycle scalable terahertz pulse source in reflection geometry

Tóth¹,

Pálfalvi²,

Tibai³

et al. 2019

Opt. Express

Self Cite

View full text Add to dashboard Cite

A tilted-pulse-front pumped terahertz pulse source is proposed for the generation of extremely high field single-cycle terahertz pulses. The very simple and compact source consists of a single crystal slab having a blazed reflection grating grooved in its back surface. Its further important advantages are the energy scalability and the symmetric THz beam profile. Generation of 50 MV/cm focused field with 5.6 mJ terahertz pulse energy is predicted for a 5 cm diameter LiNbO 3 crystal, if the pump pulse is of 450 mJ energy, 1030 nm central wavelength and 1 ps pulse duration. Such sources can basically promote the realization of THz driven electron and proton accelerators and open the way for a new generation concept of terahertz pulses having extreme high field. arXiv:1907.02462v1 [physics.optics] 4 Jul 2019The frequency range below 2 THz can be better accessed with lithium niobate (LiNbO 3 , abbreviated as LN in the followings), utilizing the tilted-pulse-front (TPF) technique for non-collinear phase matching [6]. Presently, THz pulse energy in the mJ level is available with TPF excited THz sources using LN [7].In the TPF excitation geometry, the velocity matching reads aswhere v p,gr is the group velocity of the pump pulse, v T Hz,ph is the phase velocity of the THz pulse, and γ is the pulse-front-tilt angle, which is ∼63 • for LN. LN based TPF sources have been demonstrated to be very effective and, because of this, are widely applied in THz pump-probe experiments supporting mJ level THz pulses. However, the large necessary tilt-angle and the correspondingly large angular dispersion of the pump beam mean strong limitations, namely: (i) Imaging errors in the presence of angular dispersion result in a lengthened pulse duration at the edges of the pump spot [8,9]. (ii) In order to enable perpendicular incoupling of the pump and perpendicular outcoupling of the THz beam, a prism-shaped nonlinear crystal has to be used with a wedge angle equal to the tilt angle γ. This results in THz pulses with different temporal shapes at the edges of the THz beam because of the different generation lengths. Such a bad quality, strongly asymmetric THz beam drastically hinders many applications, especially particle acceleration. (iii) Due to the large groupdelay-dispersion (GDD) [10] associated to the angular dispersion, an ultrashort pump pulse evolves very fast inside the LN crystal, and the average pulse duration becomes much longer than the Fourier transfrom-limited (FL) pump pulse duration.Problems (i) and (ii) can be eliminated, in principle, using contact-grating set-ups [11]. An efficient contact-grating set-up was realized using ZnTe semiconductor as nonlinear material [12]. Contact grating setups were designed and realized for LN, too [13,14]. However, because of technical difficulties induced by the large needed tilt angle, efficient generation of THz pulses has failed yet.In order to mitigate problem (iii) one should use semiconductor crystal, which requires lower pulse-front-tilt, or longer FL pump pulse duration can be ...

show abstract

“…One proposed approach to circumvent these limitations is to use a tilted pulse front assembled by a superposition of small, discrete, time-delayed pump beamlets. This was demonstrated in [24], and variants of the approach were studied in [25,26,27,28,29]. Conceptually, the small beamlet size in one of the transverse directions (e.g.…”

Section: Introductionmentioning

confidence: 99%

Analysis of terahertz generation by beamlet superposition

et al. 2019

View full text Add to dashboard Cite

A theory of terahertz generation using a superposition of beamlets is developed. It is shown how such an arrangement produces a distortion-free tilted pulse front. We analytically show how a superposition of beamlets produces terahertz radiation with greater efficiency and spatial homogeneity compared to tilted pulse fronts generated by diffraction gratings. The advantages are particularly notable for large pump bandwidths and beam sizes, suggesting better performance in the presence of cascading effects and for high energy pumping. Closed-form expressions for terahertz spectra and transients in three spatial dimensions are derived. Conditions for obtaining performance better than conventional tilted pulse fronts and bounds for optimal pump parameters are furnished. arXiv:1810.09118v3 [physics.optics]

show abstract

Demonstration of a tilted-pulse-front pumped plane-parallel slab terahertz source

Cited by 44 publications

References 21 publications

Laser‐Driven Strong‐Field Terahertz Sources

Laser‐Driven Strong‐Field Terahertz Sources

Single-cycle scalable terahertz pulse source in reflection geometry

Analysis of terahertz generation by beamlet superposition

Contact Info

Product

Resources

About