Center for Relativistic Laser Science

Building of the 2D IR spectrophotometer is supported by Korea Basic Science Institute (KBSI) and is installed in KBSI Seoul Center which is located at Korea University. It will be used for the cooperative study of CMSD with KBSI.

Ti:sapphire oscillator (tsunami) is used as a seed for regenerative amplifier (spitfire pro) which generates pulses (1 mJ/pulse). The half of energy is used to pump optical parametric amplifiers (OPA). The first path of the OPA in a BBO crystal is pumped with 800 nm light (~10%) and seeded by a white-light continuum, which is generated by a small fraction of the 800 nm light in a sapphire plate. Amplified by the rest of the 800 nm light in the second path through the BBO crystal, the signal and idler beams are generated. The tunable mid-IR pulses are produced from each signal-idler pair in thin AgGaS2 crystals via difference frequency generation. The pulses at 3- 6 μm (2 μJ/pulse, 60 fs) are used in the experiments.

The mid-IR beam is split into four parts to provide k1, k2, k3, and a local oscillator (LO) beams. The k1, k2, k3 pulses are focused onto the sample with a 100 mm focal length gold-coated off-axis parabolic reflector. A third-order signal generated in the sample is picked at the phase matching direction by another parabolic reflector and then mixed with the LO pulse, which is delayed by a time t. The time delays are controlled by three linear motor driven translation stages. Intensity of the third-order signal and LO interference is detected by an MCT array detector (Infrared Associates, Inc.) and digitized with a preamplifier electronics. A program to control the experiment is written using the Labview software. The polarization of the pulses is controlled by a pairs of a half-wave plate (Karl Lambrecht Corp.) and a BaF2 wire-grid polarizer (Specac Inc.).

	CW Pump Laser Spectra-Physics Milllenia CW 532 nm pump laser		Monochromator & Detector Horiba Lagacy Monochromator MCT single & 64-element array
	Femtosecond Laser Oscillator Spectra-Physics Tsunami femtosecond domain pulse source.		Lock-In Amplifier Stanford Research DSP Lock-In Amplifier
	Q-Switched Laser Spectra-Physics Enpower® Ideal for pumping Ti:sappahire amplifier		Boxcar averager
	Ultrafast Ti:sapphire Amplifier Spectra-Physics Spitfire® Pro 50 fs 800nm Pulse		Stage Controller AppliedPrecision® Nanomotion®II Micropositioning system
	Ultrafast OPA Spectra-Physics OPA-800C(BBO crystal)		Pentium 4 Computer ComputerBoard DAQ Board GPIB Card LabVIEW 8.2
	Photon Echo Setup		Chiller NESLAB Merlin M-33 Recirculating Chiller