Flash Photolysis
Nanosecond spectral dynamics of meso-Tetraphenylporphine in solution, acquired using the HARPIA-TA-FP flash photolysis module.
Measurement conditions: 1.8 kHz repetition rate, 343 nm pump wavelength, 5.4 μJ pump energy.
The flash photolysis experiment is designed for measuring long-lived states of molecular systems. It is extensively used to study light-induced processes in organic molecules, polymers, nanoparticles, semiconductors, as well as photosynthesis and light-induced conformational changes in plants and other biological systems.
The principle of flash photolysis is analogous to the femtosecond transient absorption (TA) experiment but operates with delays in the nanosecond–microsecond range. In femtosecond transient absorption, the delay between pump and probe pulses is varied by moving the mechanical delay stage, while here the delayed probe pulse is obtained from an electronically triggered external probe laser.
The HARPIA-TA spectrometer offers an optional flash photolysis extension. The exceptional optical stability of PHAROS and CARBIDE lasers, reduction of electronic jitter, and tedious analysis of experimental data enable measuring the signals with sub-10 ns temporal resolution.
