Lyhyt kuvaus
The aim of the purchase is to acquire a femtosecond laser to initiate the optical Kerr effect and trigger crystallization and chemical reactions in photoenzymes and other photoactive molecules. Femtosecond laser triggering is crucial to be able to do pump-probe measurements at synchrotrons and x-ray free-electron lasers (FELs). To match the needs of various applications at synchrotrons and FELs, the femtosecond system at approximately 1 μm must be versatile in terms of tunable laser parameters, such as pulse energy and repetition rate, over a wide range of values (e.g. single pulse to >10 kHz). Furthermore, the applications in photochemistry would require pulse lengths below 300 fs. Another application is to initiate the optical Kerr effect in aqueous solutions and probe the transient birefringence using another laser or FEL. To be able to reach the threshold of photo-ionization and plasma generation in water, pulse energies of at least 400 μJ must be available.