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Updated: May 8, 2026
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Absolute Quantum Yield Measurement of Powder Samples
Published on: May 12, 2012
Eclipsing thermal lens spectroscopy for fluorescence quantum yield measurement
C Estupiñán-López1, C Tolentino Dominguez, R E de Araujo
1Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Cidade Universitária, Recife-PE, 50740-530, Brazil.
Optics Express
|August 14, 2013
Summary
A new eclipsing detection mode enhances thermal lens spectroscopy (TLS) sensitivity for measuring fluorescence quantum yield. This method significantly improves the signal-to-noise ratio for accurate quantum yield determination.
Area of Science:
- Analytical Chemistry
- Spectroscopy
- Photochemistry
Background:
- Thermal Lens Spectroscopy (TLS) is a sensitive technique for measuring thermal properties and photothermal effects.
- Accurate determination of fluorescence quantum yield is crucial for understanding material photophysics and developing new optical materials.
- Mode-mismatched TLS setups can suffer from limited sensitivity, hindering precise quantum yield measurements.
Purpose of the Study:
- To present a modified spatial filtering method to enhance the sensitivity of single-beam, mode-mismatched TLS.
- To improve the measurement accuracy of fluorescence quantum yield using the developed technique.
- To validate the method by measuring the quantum yield of Rhodamine 6G solutions.
Main Methods:
- Implementation of an eclipsing detection mode within a TLS experimental setup.
- Detection of the external part of the laser beam transmitted through the fluorescent sample.
- Measurement of the absolute quantum yield of Rhodamine 6G (Rh6G) at varying concentrations in ethanol.
Main Results:
- The eclipsing detection mode significantly improved the signal-to-noise (S/N) ratio.
- An enhancement of the S/N ratio up to approximately 1400% was achieved for absolute quantum yield measurements.
- The method demonstrated reliable performance across a range of Rhodamine 6G concentrations.
Conclusions:
- The modified spatial filtering method, utilizing eclipsing detection, substantially enhances TLS sensitivity for fluorescence quantum yield measurements.
- This technique offers a significant improvement in signal-to-noise ratio, enabling more accurate determination of absolute quantum yields.
- The developed method is effective for characterizing fluorescent samples, as demonstrated with Rhodamine 6G.
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