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Facilities

Auxiliary Laboratories and Facilities Equipment

4. PICOSECOND TIME-RESOLVED SPECTROSCOPY SYSTEM
(6-007, Prof. Daniel Nocera)

The Department of Chemistry and the Harrison Spectroscopy Laboratory jointly support this facility. It is used mainly by the Nocera group, to study the mechanism of electron transfer in biological systems (e.g. Cytochrome C) porphyrin-based donor-acceptor systems, and by the Swager Group, to examine the sensing mechanism of TNT sensors.

Hamamatsu C4334 Streak Scope Streak Camera System with Coherent Mode-locked Ti:Sapphire Laser
The streak camera system consists of 3 major components: (1) the streak scope camera (Hamamatsu model C4334-01), designed to take the spectral image from the spectrograph and convert it into a two-dimensional image that includes time as a second axis; (2) the imaging spectrograph (Chromex model 250is), with 3 gratings (100 lines/mm 780nm blaze; 100 lines/mm 450 blaze; 300 lines/mm 500nm blaze), which are software selectable and tunable; (3) the delay unit (Hamamatsu Model C1097-04), that allows delays of up to 32ns in steps of 30ps for use on 1, 2 and 5ns time scales. A second delay unit (Stanford Research Systems DG535) allows for delays on time scales of 10ns and higher. The camera, spectrograph and delay generators are all controlled by the program (Hamamatsu HPD-TA) on a PC. Analysis of the data is also possible using the same software package, which includes "fluorescence lifetime fitting module for HPD-TA" (Hamamatsu TA-Fit) lifetimes with a resolution of ~50ps and a window up to 1ms limited by the laser repetition rate. The streak camera is capable of measuring time-resolved emission spectra over a 100 nm wavelength range in real time. This makes direct comparison of kinetics of different spectral features possible.