11. Laser Induced Opto Acoustic Spectroscopy (LIOAS) Setup
The sample is excited with a ns laser pulse. Relaxation to the ground state leads to a rapid heat dissipation resulting in a pressure wave which is recorded by a fast microphone. The characteristics of this wave carry information on slowly decaying excited states.
Q-switched Nd-YAG laser system with optical parametric oscillator, detection.
This instrument provides indirect evidences for the presence and energy or quantum yield for the population of long lived excited states (e.g. triplet) which decay non-radiatively to the ground state.