Three-photon and four-photon absorption in lithium niobate measured by the Z-scan technique: erratum.

A misprint in our manuscript published in Opt. Express32(5), 7030 (2024) 10.1364/OE.

Easily variable and scalable terahertz pulse source based on tilted-pulse-front pumped semiconductors.

A new type of terahertz source containing only two optical elements - a volume phase holographic grating, and a semiconductor nonlinear slab - is proposed. The setup does not require any microstructuring, has only one diffraction order, and can be scaled to large pump sizes without any principal limitations. Furthermore, it can be easily adapted to different pump wavelengths and THz phase-matching frequencies.

Three-photon and four-photon absorption in lithium niobate measured by the Z-scan technique.

Open-aperture Z-scan measurements have been carried out to investigate the three-photon (3 PA) and four-photon absorption (4 PA) coefficients at 800 nm and 1030 nm wavelengths, respectively in congruent and stoichiometric lithium niobate (cLN, sLN) with different concentrations of Mg doping. The laser pulse duration at the two wavelengths were 40 and 190 fs. The peak intensity inside the crystals varied between approximately 110 and 550 GW/cm.

Demonstration of an imaging-free terahertz generation setup using segmented tilted-pulse-front excitation.

A novel, to the best of our knowledge, compact, imaging-free, tilted-pulse-front (TPF) pumped terahertz (THz) source based on a LiNbO slab with a small wedge angle (< 8°) and with an echelon microstructure on its input surface has been demonstrated. Single-cycle pulses of more than 40-µJ energy and 0.28-THz central frequency have been generated by 100-mJ, 400-fs pump pulses with 4.

Scalable microstructured semiconductor THz pulse sources.

In recent years several microstructured lithium niobate THz pulse source were suggested for high-energy applications. Two types of those, the reflective and the transmissive nonlinear slab are adopted here for semiconductors. These new sources are scalable both in THz energy and size.

Waveguide structure based electron acceleration using terahertz pulses.

We have developed a waveguide structure for electron acceleration using a few µJ energy THz pulse. The metallic device focuses the incoming linearly polarized nearly single-cycle THz pulse, hence increasing the peak electric field strength. We experimentally verified the gain and the temporal profile of the electric field in the structure using electro-optic sampling technique.

Uniformly scalable lithium niobate THz pulse source in transmission geometry.

A novel THz source, based on optical rectification in LiNbO using the tilted-pulse-front technique, is proposed and experimentally demonstrated. The pulse-front tilt is introduced by a volume phase holographic grating, efficiently used at perpendicular incidence in transmission, and the THz pulses are produced in a LiNbO plane-parallel nonlinear echelon slab, arranged parallel to the grating. As a unique feature, the entire setup has a plane-parallel, transmission-type configuration, which straightforwardly enables distortion-free scaling to large sizes, high pulse energies and high THz field strengths.

Numerical investigation of imaging-free terahertz generation setup using segmented tilted-pulse-front excitation.

Recently a hybrid-type terahertz (THz) pulse source was proposed for high energy terahertz pulse generation. It is the combination of the conventional tilted-pulse-front setup and a nonlinear crystal with a transmission stair-step echelon of period in the hundred-micrometer range etched into the front face. The tilt angle introduced by the conventional tilted-pulse-front setup (pre-tilt) was chosen to be equal to the tilt-angle needed inside the nonlinear crystal (62° for lithium niobate (LN)) in order to fulfill velocity-matching.

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

A new type of tilted-pulse-front pumped terahertz (THz) source has been demonstrated, which is based on a LiNbOplane-parallel slab with an echelon structure on its input surface. Single-cycle pulses of 1 μJ energy and 0.30 THz central frequency have been generated with 5×10 efficiency from such a source.