Determination of a Raman shift laser power coefficient based on cross correlation

Area of Science:

• Optothermal Raman spectroscopy
• Laser-induced heating
• Nanoscale thermal transport

Background:

• Accurate determination of the laser heating-induced Raman shift laser power coefficient (ψ) is crucial for energy transport state-resolved Raman (ET-Raman) methods.
• Traditional curve-fitting methods for determining ψ can be prone to errors, limiting the reliability of micro/nanoscale thermal measurements.

Purpose of the Study:

• To introduce a novel, robust cross-correlation technique for precise determination of the laser power coefficient ψ.
• To enhance the accuracy and reliability of optothermal Raman-based methods for micro/nanoscale thermal analysis.

Main Methods:

• A cross-correlation technique was developed, measuring similarity between experimental intensity data and a test Gaussian signal.
• This method bypasses potential errors associated with curve fitting by directly identifying the peak location.
• The technique provides a global treatment of Raman spectra for improved data processing.

Main Results:

• The cross-correlation method accurately and quickly determines the Raman peak location and the laser power coefficient ψ.
• This approach circumvents errors inherent in traditional curve-fitting techniques.
• The method offers a significant improvement in the reliability of optothermal Raman-based measurements.

Conclusions:

• The novel cross-correlation technique provides a reliable and efficient method for determining the laser power coefficient ψ.
• This advancement improves the accuracy of micro/nanoscale thermal measurements using ET-Raman spectroscopy.
• The technique offers a robust data processing approach for Raman spectra analysis.