Saturation in laser excited atomic fluorescence spectrometry: experimental verification

Area of Science:

• Atomic and Molecular Physics
• Laser Spectroscopy
• Quantum Optics

Background:

• Laser-induced fluorescence is a widely used analytical technique.
• Achieving energy level saturation is crucial for maximizing fluorescence signals.
• Deviations from theoretical models can occur due to experimental conditions.

Purpose of the Study:

• To report measurements of fluorescence signal versus laser power.
• To investigate the shapes of experimental log B(F) vs log E(nu) curves.
• To compare experimental results with theoretical predictions for laser saturation.

Main Methods:

• Experimental measurements of fluorescence signal as a function of laser power.
• Log-log plotting of fluorescence radiance (B(F)) versus laser energy density (E(nu)).
• Analysis of curve departures from a slope of unity to infer saturation.

Main Results:

• Observed deviations from a slope of unity in log-log plots indicate saturation.
• Failure of the fluorescence curve to "roll over" results in the loss of maximum fluorescence radiance (B(F max)).
• Experimental curve shapes and absolute values were analyzed in relation to theoretical models.

Conclusions:

• Understanding the relationship between laser power and fluorescence is key to optimizing measurements.
• The study provides insights into the conditions under which laser saturation deviates from ideal theory.
• Accurate theoretical modeling is essential for interpreting experimental fluorescence data.