Determination of the carrier-envelope phase of few-cycle laser pulses with terahertz-emission spectroscopy

Kreß, M.; Löffler, Thomas; Thomson, Mark D.; Dørner, R.; Gimpel, H.; Zrost, K.; Ergler, Thorsten; Moshammer, R.; Morgner, Uwe; Ullrich, J.; Roskos, Hartmut G.

doi:10.1038/nphys286

Cited by 239 publications

(102 citation statements)

References 32 publications

(42 reference statements)

Supporting

Mentioning

100

Contrasting

Order By: Relevance

“…It has been recently possible to produce laser pulses with the relative carrier-to-envelope phase (CEP) [27]. For such pulses the electric field has the form: E(t) = E(t) sin(ω L t + φ CEP ), where E(t) is the Gaussian envelope and φ CEP is the carrier-to envelope-phase.…”

Section: Discussionmentioning

confidence: 99%

Zitterbewegung of electrons in carbon nanotubes created by laser pulses

Rusin¹,

Zawadzki²

2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract. We describe a possibility of creating non-stationary electron wave packets in zigzag carbon nanotubes (CNT) illuminated by short laser pulses. After disappearance of the pulse the packet experiences the trembling motion (Zitterbewegung, ZB). The band structure of CNT is calculated using the tightbinding approximation generalized for the presence of radiation. Employing realistic pulse and CNT parameters we obtain the ZB oscillations with interband frequencies corresponding to specific pairs of energy bands. A choice of optimal parameters is presented in order to observe the phenomenon of ZB experimentally. The use of Gaussian wave packets to trigger the electron Zitterbewegung, as used in the literature, is critically reexamined.

show abstract

Section: Discussionmentioning

confidence: 99%

Zitterbewegung of electrons in carbon nanotubes created by laser pulses

Rusin¹,

Zawadzki²

2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…In this mechanism, tunneling ionization and subsequent electron motion produce a quasi-dc photoinduced current, which in turn emits THz radiation. The quasi-dc plasma current can be efficiently produced in a gas irradiated with two-color laser pulses [5][6][7][8][9][10][11][12][13][14], in multicolor pump schemes [16] and in chirped [17] or few-cycle pulses [18,19]. There are other, generally less efficient mechanisms for THz generation in gases that employ single-color pumps.…”

Section: Introductionmentioning

confidence: 99%

Tailoring terahertz radiation by controlling tunnel photoionization events in gases

et al. 2011

View full text Add to dashboard Cite

Applications ranging from nonlinear terahertz spectroscopy to remote sensing require broadband and intense THz radiation which can be generated by focusing two-color laser pulses into a gas. In this setup, THz radiation originates from the buildup of the electron density in sharp steps of attosecond duration due to tunnel ionization, and subsequent acceleration of free electrons in the laser field. We show that the spectral shape of the THz pulses generated by this mechanism is determined by superposition of contributions from individual ionization events. This provides a straightforward analogy with linear diffraction theory, where the ionization events play the role of slits in a grating. This analogy offers simple explanations for recent experimental observations and opens new avenues for THz pulse shaping based on temporal control of the ionization events. We illustrate this novel technique by tailoring the spectral width and position of the resulting radiation using multi-color pump pulses.

show abstract

“…Our results show that THz conversion via tunnel ionization can be greatly improved with well-designed multicolor pulses. DOI: 10.1103/PhysRevLett.114.183901 PACS numbers: 42.65.Re, 32.80.Fb, 52.50.Jm Ultrashort pulses in the terahertz (THz) range (from ∼0.1 to ∼30 THz) are extremely important for various timeresolved studies in molecular physics, chemistry, material sciences, and security applications [1][2][3][4][5][6][7][8]. One of the major challenges in this field is the development of THz emitters producing high peak intensities.…”

mentioning

confidence: 99%

Boosting Terahertz Generation in Laser-Field Ionized Gases Using a Sawtooth Wave Shape

et al. 2015

View full text Add to dashboard Cite

Broadband ultrashort terahertz (THz) pulses can be produced using plasma generation in a noble gas ionized by femtosecond two-color pulses. Here we demonstrate that, by using multiple-frequency laser pulses, one can obtain a waveform which optimizes the free electron trajectories in such a way that they acquire the largest drift velocity. This allows us to increase the THz conversion efficiency to 2%, an unprecedented performance for THz generation in gases. In addition to the analytical study of THz generation using a local current model, we perform comprehensive 3D simulations accounting for propagation effects which confirm this prediction. Our results show that THz conversion via tunnel ionization can be greatly improved with well-designed multicolor pulses. DOI: 10.1103/PhysRevLett.114.183901 PACS numbers: 42.65.Re, 32.80.Fb, 52.50.Jm Ultrashort pulses in the terahertz (THz) range (from ∼0.1 to ∼30 THz) are extremely important for various timeresolved studies in molecular physics, chemistry, material sciences, and security applications [1][2][3][4][5][6][7][8]. One of the major challenges in this field is the development of THz emitters producing high peak intensities. So far, besides conventional devices such as antennas, photoconductive switches, etc., two main techniques have been explored for producing subps THz pulses with energies in the microjoule range. The first method is based on optical rectification in second-order nonlinear crystals [9]. Pumped by multi-mJ single color pulses, this technique requiring phase matching can generate THz pulses with 10 μJ energy, but the bandwidth is limited to a few THz. Recently, large-sized organic crystals were used to deliver THz pulses with GV=m electric field strength, and a conversion efficiency of about 1% was demonstrated [10]. The second method is based on focusing a femtosecond pulse together with its second harmonic into a gas cell and create a plasma [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In such two-color pump setup, free electrons produced by tunnel ionization acquire a nonzero drift velocity and generate a quasi-dc current which is responsible for THz emission [19]. The mechanism underlying THz generation in gases is intrinsically related to the optically induced stepwise increase of the free electron density near the extrema of the ionizing optical field [15,16,22]. An easy explanation is that the Fourier transform of a steplike function in time has its maximum near the zero frequency. Besides, critical for the generated THz energy is a pronounced asymmetry in time of the pump wave shape with respect to the field extrema, which dictates the electron drift velocity. This gas-based scheme for THz generation provides higher breakdown threshold and broader spectral ranges than the method involving crystals [11][12][13][17][18][19][20]. THz pulses in gases with high field strength > 1 GV=m were simulated in [16]; however, the highest reported THz energies (5 μJ) correspond to conversion efficiencies of about 10 −4 only.In this Let...

show abstract

Determination of the carrier-envelope phase of few-cycle laser pulses with terahertz-emission spectroscopy

Cited by 239 publications

References 32 publications

Zitterbewegung of electrons in carbon nanotubes created by laser pulses

Zitterbewegung of electrons in carbon nanotubes created by laser pulses

Tailoring terahertz radiation by controlling tunnel photoionization events in gases

Boosting Terahertz Generation in Laser-Field Ionized Gases Using a Sawtooth Wave Shape

Contact Info

Product

Resources

About