This repository contains exemplary code to generate and fit photon arrival time histograms from time correlated single photon counting (TCSPC) measurements for two TCSPC-raw-data formats (SPC and PTU, 1 sample data file each provided) that were used in [1]. Binary data is imported into MATLAB (currently deployed version R2025b) by the "parsePTUFile.m" and "parseSPCFile.m" functions respectively, as demonstrated in the scripts "fitGlobalHistogramFrom*.m", which also perform fitting and plotting of the sample data. Additionally, a file for the simulation of water heating by a 1470-nm IR laser coupled to thermal dissipation by conduction and convection (via laminar flow) in COMSOL Multiphysics as used in [1] is provided.

Files in this repository:
parsePTUFile.m -- convert binary PTU-data file of photon arrival times to Matlab structure
parseSPCFile.m -- convert binary SPC-data file of photon arrival times to Matlab structure
tcspcIRF.m -- adapted from [2]: 5-parameter IRF-model based on a gaussian with asymmetric flanks
convTCSPCMonoDecay.m -- convolution of tcspcIRF.m with a mono-exponential decay, also adapted from [2]
fitGlobalHistogramFromPTU.m -- sample code to generate a histogram from PTU-data and fit it to 2 different models
fitGlobalHistogramFromSPC.m -- sample code to generate a histogram from SPC-data and fit it to 2 different models
SampleFile_01.ptu -- part of the data used in Fig. 1
SampleFile_02.spc -- part of the data used in Fig. 3
IRwaterheating.mph -- Simulation of water heating and thermal dissipation in COMSOL multiphysics

[1] "Robust thermometry-imaging at sub-micrometer and millisecond-resolution by fluorescence lifetime microscopy allows for additional acquisition of multiple imaging channels", submitted
[2] "Precise measurement of protein interacting fractions with fluorescence lifetime imaging microscopy", Mol. BioSyst. 2011, 7, 322-336; DOI: 10.1039/c0mb00132e