Development of a tunable UV laser system synchronizing precisely with synchrotron radiation pulses from UVSOR

Area of Science:

• Atomic, Molecular, and Optical Physics
• Physical Chemistry
• Materials Science

Background:

• Synchronized laser and synchrotron radiation sources are crucial for advanced time-resolved spectroscopy.
• Precise temporal control over interacting photon pulses is essential for studying fast dynamic processes.

Purpose of the Study:

• To develop and validate a combined laser-synchrotron radiation system for pump-probe experiments.
• To investigate the temporal dynamics of photodissociation and photoionization processes.
• To demonstrate the capability of the technique for studying short-lived excited states.

Main Methods:

• Mode-locked Ti:sapphire laser synchronized with UVSOR storage ring.
• Coaxial introduction of laser (243-280 nm) and undulator synchrotron radiation.
• In situ monitoring of photon pulse temporal profiles.
• Adjustable electronic module for 0-11 ns delay control with phase-locked loop stabilization.

Main Results:

• Successful synchronization and temporal overlap control of laser and synchrotron radiation pulses.
• Demonstrated pump-probe experiments on iodomethane photodissociation and helium atom ionization.
• Observed enhanced He+ signal in a narrow time window, indicating short-lived resonant states.

Conclusions:

• The developed laser-synchrotron radiation combination technique is reliable and feasible for time-resolved studies.
• The method provides high temporal resolution for investigating ultrafast phenomena.
• The technique is effective for characterizing short-lived excited states, such as He*(1s2p 1P).