Observation of terahertz coherent edge radiation amplified by infrared free-electron laser oscillations

AbstractA coupling device, which can extract coherent edge radiation (CER) from an optical cavity for a free-electron laser (FEL) without damaging the FEL due to diffraction loss, was developed at Nihon University. We successfully observed the CER beam with a power of 1 mW or more in the terahertz range during FEL oscillation. It is revealed that the CER power changed with the detuning of the optical cavity and the dependence of the CER power on the detuning length differs from that of the FEL power. The measured CER spectra indicate that the longitudinal electron distribution in a bunch is modulated by the FEL oscillation with a period corresponding to the FEL slippage length. We herein report the characteristics of the CER with FEL oscillation in detail. These results demonstrate that the CER is excellent tool to reveal the overall effect of FEL interaction on electron distribution in a bunch.

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Approaching Terahertz Holography Using the Free Electron Laser

Siberian Journal of Physics ◽

10.54362/1818-7919-2010-5-4-98-102 ◽

2010 ◽

Vol 5 (4) ◽

pp. 98-102

Author(s):

Yuliya Yu. Choporova ◽

Maxim G. Vlasenko ◽

Vasily V. Gerasimov ◽

Boris A. Knyazev ◽

Aleksandr A. Nikitin ◽

...

Keyword(s):

Free Electron ◽

Free Electron Laser ◽

Quantum Cascade Lasers ◽

Imaging Techniques ◽

Reference Beam ◽

Image Sensors ◽

Terahertz Range ◽

Terahertz Region ◽

Series Of Experiments ◽

Cascade Lasers

Many experiments in the terahertz region have been performed using low-power shot-pulse wideband sources. Appearance of more intense monochromatic terahertz sources (quantum cascade lasers, free electron lasers) and terahertz image sensors enables the implementation of classical variants of optical techniques in the terahertz range. In this paper we describe a series of experiments to demonstrate feasibility of classic holography at the terahertz range using the Novosibirsk free electron laser. Two imaging techniques have been applied for digital hologram recording. A modified MachZehnder interferometer has been fabricated for recording the reference-beam holograms. In-line holograms have been recorded and reconstructed

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Application Of Systems With Total Internal Reflection At Novosibirsk Free Electron Laser For Spectroscopy In The Terahertz Range

Siberian Journal of Physics ◽

10.54362/1818-7919-2016-11-3-72-82 ◽

2016 ◽

Vol 11 (3) ◽

pp. 72-82

Author(s):

Vasily Gerasimov ◽

Elvira Grigorieva ◽

Boris Knyazev ◽

Yuliya Choporova

Keyword(s):

Free Electron ◽

Free Electron Laser ◽

Quantum Cascade Lasers ◽

Attenuated Total Reflection ◽

Terahertz Range ◽

Optical Systems ◽

Early Diagnosis Of Cancer ◽

Infrared Spectral ◽

Atr Spectroscopy ◽

Spectral Ranges

Attenuated total reflection (ATR) spectroscopy is widely used in the visible and infrared spectral ranges. Progress in the development of laboratory scale monochromatic sources of terahertz radiation, such as quantum cascade lasers, suggests that in the near future this kind of spectrometers will be widely spread in the terahertz range. For this reason, the development of ATR based methods and devices is highly relevant. In this paper, we discuss the features of the use of ATR spectroscopy in the terahertz range, and describe some of the optical systems, designed for experiments at the Novosibirsk free electron laser (NovoFEL). We show that in the terahertz range the ATR spectroscopy has a number of significant advantages over the absorption spectroscopy. As an example, we are discussing the possibility of using terahertz polarimetry to develop a method for early diagnosis of cancer via the detection of left-handed to right-handed polysaccharide enantiomers ratio. Spectra of selected polysaccharides were recorded with a standard Fourier spectrometer using developed by us an ATR unit. The possibility of studying the polarization characteristics of polysaccharides in aqueous solutions using spectrally selective polarimeter with the NovoFEL as a tunable radiation source was demonstrated.

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