Evaluation of an attenuation system for an infrared free-electron laser

Abstract

This study concerns the attenuation of the incident power from a free-electron laser ͑FEL͒ in steps of up to two orders of magnitude, while maintaining optical beam geometry. We have developed and evaluated the properties of a FEL attenuation filter system, which can be attached and detached, with the position of the focusing lens and the target sample fixed. As a result, we have established that our FEL attenuation filter system enables two orders of magnitude of power control for infrared wavelengths between 5.5 and 6.5 m. We conclude that the attenuation system is extremely useful for various FEL applications.

Development of an Intravascular Laser Treatment with an Infrared Free Electron Laser

“…We applied FEL irradiation to slices of human arterial atherosclerosis and evaluated the effectiveness of selective removal of cholesterol esters by changes in the infrared absorption spectra using microscopic transmission FTIR (Fourier Transform Infrared) spectroscopy. The peak in the infrared absorption spectrum derived from the intermolecular stretching vibration specific to an ester bond of cholesterol ester exists near 5.75 µm [6][7][8] .…”