Terahertz-based retrieval of the spectral phase and amplitude of ultrashort laser pulses

Abstract

Terahertz (THz) radiation is of great interest for a variety of applications, e.g., particle accelerations, spectroscopy investigations of quantum systems, and high-field study of materials. One of the most common laser-based processes to produce THz pulses is optical rectification, which transduces an infrared pump laser to the THz domain (0.1-20 THz). In this work, we propose and theoretically describe a method to characterize the amplitude and phase of the electric field of the pump laser pulse relying on THz generation and detection. We demonstrate with a numerical example how THz radiation can be used as diagnostics to characterize laser pulses with temporal length at the femtosecond level.

THz Pulsed Imaging in Biomedical Applications

“…OR ensures the THz broadband generation through NLO centrosymmetric crystals [70][71][72], extended from 0.1 THz and beyond 40 THz [57,79,80], such as organic NLO crystals. 4-N,N-dimethylamino -4'-N'-methyl -stilbazolium 2,4,6-trimethylbenzenesulfonate (DSTMS) [81][82][83][84] and 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium tosylate (DAST) show efficient generation from 0.3 to >16 THz in the phase-matching condition between 720 nm and 1650 nm. The NLO materials need to have high second-order NLO susceptibility, high transparency at both pump and THz frequency, and high optical damage threshold, in order to satisfy the phase-matching condition between the fundamental optical pump and generated THz waves [85,86].…”

Broadband Anisotropic Optical Properties of the Terahertz Generator HMQ-TMS Organic Crystal

“…The latter realm has been the starting point for the production of single cycle, high-intensity THz signals comparable to those obtained from free-electron facilities [13,14]. The process of difference frequency generation [15,16] or optical rectification (OR) [15,[17][18][19][20][21][22] still holds the greatest interest due to its capabilities of reaching electric field magnitudes up to tens of MV/cm providing a broad THz spectral range going from nearly 0.1 THz up to 15 THz [1,23]. Due to these properties, novel NLO materials have been highly investigated in terms of THz transparency and linear and nonlinear optical responses.…”

Beam-based sub-THz source at the CERN linac electron accelerator for research facility

“…Another important kind of beam-based sources are free electron lasers [19][20][21][22][23][24], nevertheless not treated in this work. Laser-based sources are related to the optical rectification (or even to the difference frequency generation) of infrared pump lasers (fs) propagating through non-linear crystals [25]. Laser-based sources currently retain the primacy in terms of energy per pulse delivered, obtained by use of optical rectification of TW-class pump lasers in organic crystals, and therefore in terms of intensity and associated electric fields generated (up to 1 GV=m [26]).…”

“…Spectral and temporal shaping are two aspects which are intimately connected in this kind of THz radiation studies, due to the temporal coherence. Shaping by lasers is possible by acting on the temporal structure of the pump laser pulses [27,28], on their non-linear spectral phase [25] or even exploring different kind of crystal compositions and size. Shaping by electron beams is performed by inducing modulations on the bunch structure at the picosecond level.…”