Advanced microscopy
Transient absorption microscopy
Transient absorption microscopy adds a spatial resolution to the quantitative characterization of time-dependent absorption of an optically excited sample.
Introduction
What is transient absorption microscopy?
The transient absorption (TA) experiment allows for the quantitative characterization of time-dependent absorption of an optically excited sample. This technique requires two light pulses: a femtosecond narrow-bandwidth pump pulse to excite the sample and a delayed broad-bandwidth probe pulse to measure the changes in sample transmittance. The resulting difference absorption signal is measured as a function of the probe wavelength and the temporal delay between the pump and probe pulses.
What the spectrum shows
The transient absorption spectrum is much more elaborate than, e.g., a steady-state absorption or fluorescence decay spectrum. It provides information not only on the excited states of the system but also on all the intermediate evolutionary transients and non-emissive states in both the ground and excited states. Transient absorption microscopy adds spatial resolution to that same measurement.
