Optical pump-probe X-ray absorption spectroscopy

Optical pump-probe studies combine the use of both synchrotron radiation and laser light. The methods are ideally suited to conjugated systems, where analysis of individual phases is needed, but where in normal synchrotron studies several phases are being probed simultaneously.

Pump-probe OD-XASmeasurements are being carried out on a variety of systems, including bulk natural silicates that have become phase exsolved on submicroscopic scales, and nanomaterials such as core-shell quantum dot systems or oxidised porous silicon. In the former example, the optical pump-probe experiments work by using the laser to probe different defects in the exsolved phases (allowing the OD-XASof each phase to be probed) whereas in the quantum systems, the laser locally floods the electron populations in individual phases.

Lasers being employed range from the infrared (850nm) to ultra-violet (404nm); in principal, any synchrotron energy can be used where useful information can be gained (e.g. across the core-level energies of the bulk/defect atoms of interest). Optical pump-probe studies are only just being explored at Daresbury at the present time.

station 6.1station 4.2station 3.4 station 3.2 station 1.1