F. Blanchard

Single-cycle terahertz pulses with amplitudes exceeding 1 MV/cm generated by optical rectification in LiNbO3

Using the tilted-pump-pulse-front scheme, we generate single-cycle terahertz (THz) pulses by optical rectification of femtosecond laser pulses in LiNbO3. In our THz generation setup, the condition that the image of the grating coincides with the tilted-optical-pulse front is fulfilled to obtain optimal THz beam characteristics and pump-to-THz conversion efficiency. By using an uncooled microbolometer-array THz camera, it is found that the THz beam leaving the output face of the LN crystal can be regarded as a collimated rather than point source. The designed focusing geometry enables tight focus of the collimated THz beam with a spot size close to the diffraction limit, and the maximum THz electric field of 1.2 MV/cm is obtained.

Generation of 1.5 µJ single-cycle terahertz pulses by optical rectification from a large aperture ZnTe crystal

We demonstrate the generation muJ-level, single-cycle terahertz pulses by optical rectification from a large-aperture ZnTe single crystal wafer. Energies up to 1.5 muJ per pulse and a spectral range extending to 3 THz were obtained using a 100 Hz Ti:sapphire laser source and a 75-mmdiameter, 0.5-mm-thick, (110) ZnTe crystal, corresponding to an average power of 150 muW and an energy conversion efficiency of 3.1 x 10(-5). We also demonstrate real-time imaging of the focused terahertz beam using a pyroelectric infrared camera.

Nonlinear ultrafast modulation of the optical absorption of intense few-cycle terahertz pulses in n-doped semiconductors

We use an open-aperture

Generation of Intense Terahertz Radiation via Optical Methods

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Terahertz pulse induced intervalley scattering in photoexcited GaAs

scan technique to show how intense few-cycle terahertz pulses can experience a nonlinear bleaching of absorption in an

Real-time terahertz near-field microscope

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Improved terahertz two-color plasma sources pumped by high intensity laser beam

-doped semiconductor due to terahertz-electric-field-driven intervalley scattering of electrons in the conduction band. Coherent detection of the transmitted terahertz pulse wave form also allows the nonlinear conductivity dynamics to be followed with subpicosecond time resolution. Both the

Near-field THz imaging of free induction decay from a tyrosine crystal

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Intense terahertz generation at low frequencies using an interdigitated ZnSe large aperture photoconductive antenna

scan and time-domain results are found to be in agreement with our theoretical analysis.

Terahertz pulse generation from bulk GaAs by a tilted-pulse-front excitation at 1.8 μm

The development of new sources in the terahertz (THz) spectral region has attracted much attention over the past 20 years. In particular, the last three years have seen a surge of new laser-based techniques for generating intense, few-cycle THz pulses in the microjoule energy range, thus paving the way to the study of the nonlinear optical properties of various materials at THz frequencies. Simultaneously, innovative solutions for broad-band THz detection were found, allowing one to sense matter in the THz range with an unprecedented time resolution. In this paper, we will attempt to give a review of the properties and characteristics of the recently developed intense THz sources, with a particular eye on their potential application in ultrafast THz nonlinear spectroscopy.