Ultrafast spectroscopy is undertaken on equipment in our femtosecond facility. We have a number of fixed experimental setups and a number of adaptable areas, allowing flexible experiments to be created that combine features from different pieces of equipment in the lab. Currently the lab has the following experiments running:
Hamamatsu Streak Camera – Detection of luminescence from thin films or solutions, with an instrument response function of ~ 2 ps (FWHM).
CDP FOG 100 – Optical gating allows luminescence to be detected on the femtosecond timescale. By sum-frequency mixing of the gating pulse and sample luminescence, upconverted light is produced that is detected. This technique allows temporal luminescence kintetics with time constants as low as 50 fs to be resolved.
Homebuilt Transient Absorption – Utilising two beams, a pump and a probe, with one of them delayable, allows transient kinetics in the absorption of samples to be recorded on the femtosecond timescale.
The labs are comprised of the following apparatus:
• Light Sources:
• Spectra Physics MaiTai Ti:Sapphire oscillator – 80 MHz output, 750-850 nm 100 fs (FWHM) pulse width.
• Spectra Physics Merlin laser – 527 nm, 50 kHz, 200 ns pulse width.
• Light Amplifiers:
• Spectra Physics Hurricane – 5 kHz 1 W output, 800 nm, 100 fs pulses.
• Spectra Physics OPA (pumped by Hurricane) – 250 nm – 10 micron tuneability, 100 fs.
• Light Conversion TOPAS-White (pumped by Hurricane) – computer controlled non-collinear parametric amplifier, giving tuneable emission from 500-1000 nm, ~40 fs pulse width.
• Homebuilt NOPA – 500-900 nm, 300 fs pulses.
• Spectra Physics Spitfire – Regenerative amplifier, pumped by Ti:Sapphire oscillator and Merlin laser.