Laser Laboratory

The Department of Chemistry's picosecond and nanosecond laser laboratory, headed by Dr. Thomas Netzel, is unique in the Southeast.  The lab features features a picosecond transient absobance laser system with 15-Hz excitation capability provided by 25-ps duration light pulses at the Nd/YAG harmonics of 532, 355, and 266 nm.  The observation wavelength and time ranges are, respectively, 360 - 800 nm and 30 ps - 15 ns.  The Nd/YAG harmonic pulses also provide excitation pulses for a stand-alone time resolved emission system with 80 ps time resolution.  Emission signal averaging is provided by a Techtronix SD1000 digitizer.  A 2001 acqusition funded by the Georgia Research Alliance is an LP900 Spectral Mode Laser Flash Photolysis System jointly manufactured by Edinburgh Instruments and Continnum.  This versatile kinetics system has an observation time range of 1 ns - 10 ms.  Its ND6000/UVT high-energy dye laser/harmonic generator subsystem can excite samples anywhere in the 270 - 900 nm range.  Observation wavlengths span the 200 - 900 nm range via a PMT coupled to a Tektronix digitizer.  Finally, its ICCD camera can record transient absorbance spectra over a 270 nm window in a single, laser shot with a variable time window that can be as short as 5 nanoseconds.  Current research focuses on studying photoinduced charge transport in covalently modified DNA duplexes; this research is directed toward developing ultrasensitive viral diagnostic tests.

Picosecond Transient Absorbance Equipment
"Continuum end" of the picosecond TA kinetics laser table in experimental bay one.  The right side of the picture shows the granite mounted, Anorad delay line with a retroreflector prism on its translation stage.  The air-bearing controlled translation stage varies the light path of the 355-nm excitation beam and produces experimental delay times ranging from -300 ps (before sample excitation) to +15.5 ns (when the stage is moved fully to the other end of the granite support).  Intense 532-nm laser pulses are focused into the 20-cm long liquid cell in the center of the picture to produce continuous probe wavelengths ("continuum light") from 360 - 750 nm.
Take a picture tour of Dr. Netzel's laboratory.