When I was doing Raman spectroscopy, I observed that for the same sample (thin film), using two different laser sources gave different Raman spectra. We know Raman Shift is materially dependent property.What could be the reason for difference in Raman spectra?
Laser sources were the He-Cd laser (λ=325 nm), i.e., UV light source, and the He-Ne laser (λ=633 nm), i.e., visible light source.
The answer is obvious to me. Just for curiosity, I asked ChatGPT the question and here is the answer :-)
In summary, the choice of laser source in Raman spectroscopy directly impacts the excitation conditions and interaction mechanisms between light and matter, leading to variations in the observed Raman spectra for the same sample. Understanding these factors is crucial for interpreting Raman data accurately and extracting meaningful information about the sample's molecular structure and composition.
Fairly common effect. Often due to resonance issues. Take a look at graphene Raman spectra - well documented changes with excitation frequency. However, it doesn't look like you have much change in the figures that couldn't just be sample prep issues.
There is another possibily for the difference, i.e. calibration. You should0 perform calibration for each laser before measurements if applicable. In addition, detectors can have different property profiles, like sensitivity. This could cause the difference in the measured raman