Tapped delay line time-to-digital converters calibration based on Geiger-mode avalanche photodiode

Field Programmable Gate Array (FPGA) based Tapped Delay Line (TDL)- Time-to-Digital Converters (TDC) are widely used in photoelectric measurement due to flexible design and low cost. These types of TDCs require calibration to quantify the inconsistent bin width of the delay line for better accuracy. This paper proposes a code density method based on Geiger-Mode Avalanche Photodiode (GM-APD) avalanche signals for calibration. The paper analyzes the Poisson distribution of GM-APD’s avalanche signals. Then, using an experiment to verify that the proposed method is convenient and effective for TDL-TDC’s calibration, reduces the Differential Nonlinearity (DNL) and Integral Nonlinearity (INL) in measurement.