Photothermal Micro-Spectroscopy (PTMS), alternatively known as PTTF (photothermal Temperature Fluctuation), [1] [2] is derived from two parent instrumental techniques: infrared spectroscopy and atomic force microscopy (AFM). In one particular type of AFM, known as scanning thermal microscopy (see Scanning probe microscopy#sthm) [1] , the imaging probe is a sub-miniature temperature sensor, which may be a thermocouple or a resistance thermometer. This same type of detector is employed in a PTMS instrument, enabling it to provide AFM/sthm images: however, the chief additional use of PTMS is to yield infrared spectra from sample regions as small as a micrometre or less, as outlined below.

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