How to normalize an absorption spectrum

Hello to everyone, I would like to manipulate an absorption spectrum in order to "highlight" the absorption peaks of my sample. I attach the plot image, at first I thought it was an offset or a background signal, but even with the reference subtraction the signal looks like this so I thought there might be a way to reasonably normalize the curve.

Thank you in advance :)

Answer 1

[Abhimenyu]

Hi Roberta,

I understand that you want to normalise the absorption curve for highlighting the peaks. These are some possible steps you can take:

1. “findpeaks": This function will help to find the peaks and highlight them using a pointer.
2. Normalise with “max”/“findpeaks”: You can use “max” function or “findpeaks” function to find the maximum data point. You can divide your entire data by this maximum value to normalise the graph and enhance the peaks.
3. “smoothdata”: This function can help to filter out noise using various filters and help you enhance the peaks.

You can refer to the following links from MATLAB documentation to understand more about "findpeaks" and "smoothdata" functions respectively.

1. https://www.mathworks.com/help/releases/R2023a/signal/ref/findpeaks.html
2. https://www.mathworks.com/help/releases/R2023a/matlab/ref/smoothdata.html

I hope this helps!

Thank you,

Abhimenyu