CERN Accelerating science

Article
Title	Development of a Pump-Probe System using a Non-Coated ZnSe Beam Splitter Cube for an MIR-FEL
Author(s)	Heya, Manabu ; Awazu, Kunio ; Horiike, Hiroshi ; Ishii, Katsonuri ; Suzuki, Sachiko
Affiliation	(OU-iFEL, Hirakata, Osaka)
Publication	2004
In:	26th International Free Electron Laser Conference and 11th FEL User Workshop 2004, Trieste, Italy, 29 Aug - 3 Sep 2004, pp.e-proc. THPOS18
Subject category	Accelerators and Storage Rings
Abstract	A pump-probe technique is essential for a proper understanding of laser interaction with tissue and material. Our pump-probe system divides the incident mid-infrared Free Electron Laser (MIR-FEL) into two beams with equal intensity, and crosses simultaneously the two incoming beams at the same position. One is for a pump beam, another is for a probe beam. Time-resolved absorption spectroscopy involving this technique gives us information on the vibrational dynamics of molecules. We have developed this system for an MIR-FEL using a non-coating ZnSe beam splitter cube. The beam splitter cube is composed of two ZnSe prisms in the shape like a trapezoid. The two pulses with equal intensity are generated due to Fresnel reflection and transmission at the boundary between two prisms, then are reflected due to total reflection at other side boundaries between each prism and air, and illuminate simultaneously the same spot. We have conducted a proof-of-concept of experiment of this system using an MIR-FEL. We showed that this system is applicable for a broad waveband (6-11 μm). Thus, we proved that this system without complicated optical alignment is useful for absorption spectroscopy.