Cerenkov radiation as a UV and visible light source for time-resolved fluorescence

Area of Science:

• Atomic, Molecular & Optical Physics
• Physical Chemistry
• Spectroscopy

Background:

• Fluorescence lifetime measurements are crucial for understanding molecular dynamics.
• Conventional methods often require high excitation intensity or complex setups.
• A need exists for sensitive and robust fluorescence lifetime measurement techniques.

Purpose of the Study:

• To demonstrate the first application of Cerenkov radiation for fluorescence lifetime measurements.
• To develop a novel excitation source for time-resolved fluorescence spectroscopy.
• To assess the accuracy and efficiency of this new method.

Main Methods:

• Utilizing relativistic beta particles from 90Sr/90Y decay to generate Cerenkov radiation in a quartz waveguide.
• Employing a digitally based cross-correlation signal processor for data analysis.
• Characterizing the temporal and spectral properties of the Cerenkov light pulses.

Main Results:

• Accurate fluorescence lifetime measurements were achieved with low excitation intensity and short integration times.
• The method proved effective for various compounds across UV and blue spectral regions.
• The Cerenkov radiation pulses were characterized with durations under 100 picoseconds.

Conclusions:

• Cerenkov radiation is a viable and effective excitation source for fluorescence lifetime measurements.
• This technique offers advantages in sensitivity and simplicity compared to traditional methods.
• Potential for future improvements and broader applications in time-resolved fluorescence studies.