photothermal spectroscopy 

https://doi.org/10.1351/goldbook.08659
Measurement method of spectroscopy in which the absorption of electromagnetic radiation by a sample is detected as a result of the heat generated by the absorption.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 759 [Terms] [Paper]