Nonlinear absorption of coherent resonance radiation in pink ruby

Area of Science:

• Solid-state physics
• Laser spectroscopy
• Materials science

Background:

• The R(1) doublet in pink ruby is crucial for understanding its optical properties.
• Previous studies lacked high-resolution spectral analysis under intense monochromatic light.

Purpose of the Study:

• To investigate the high-resolution absorption spectrum of pink ruby using a tunable laser.
• To analyze the effects of high laser intensity on ruby's optical absorption and spectral features.

Main Methods:

• Utilized a temperature-controlled ruby laser as a monochromatic source for high-resolution spectroscopy.
• Oriented ruby crystals for alpha-polarized radiation absorption measurements near liquid nitrogen temperature.
• Employed time-resolved spectral measurements to observe dynamic changes.

Main Results:

• Observed a decrease in absorption coefficient with increasing laser intensity, indicating ground state depletion.
• Noted a significant reduction in spectral spacing between R(1) doublet components at high laser intensities.
• Detected temporal structuring in output beams emerging from the sample, even when incident beams were smooth.

Conclusions:

• Ground state depletion model successfully explains the reduced absorption coefficient.
• Further theoretical development is needed to explain spectral spacing changes and temporal structuring.
• High-intensity laser interaction with ruby presents complex phenomena requiring deeper investigation.