Compact Time-to-Digital Converter Kit for Fluorescence Lifetime Measurements

Fluorescence lifetime measurement is a powerful technique for studying the dynamics of physical, chemical, and quantum systems by analyzing fluorescence decay. However, such measurements traditionally require time-correlated single-photon counting (TCSPC) modules, which are expensive and often lack flexibility. In this work, we present the use of a compact, cost-effective time-to-digital converter (TDC) module designed for fluorescence lifetime spectroscopy and imaging applications, accessible through a custom Python API. The module integrates a Texas Instruments TDC7200 chip and an MSP430 microcontroller, offering a photon detection rate of up to 10 kHz, with a timing resolution of less than 110 ps full width at half maximum. To validate its performance, the module was tested using reference samples such as fluorescein dye and calibration beads. Designed as a standalone upgrade, this TDC module can be easily incorporated into existing microscopes or spectroscopes, enabling lifetime measurement for biophysics and materials research.