Design of a high speed pseudo-random bit sequence based time resolved single photon counter on FPGA

Diffuse optical tomography is a rapidly developing imaging technology for biomedical research and clinical studies. A commonly used technique for detecting diffused photons is time correlated single photon counting mechanism, which time stamps the photons while capturing signal. However, time stamping requires an extremely long data acquisition time. Using a spread-spectrum approach, a novel time correlated single photon counting algorithm based on pseudo random bit sequences has been proposed as a solution. This paper describes a FPGA implementation of this pseudo random bit sequence based single photon counter, leveraging the rapid prototyping capabilities of reconfigurable computing. The design consists of a high speed pseudo random number generator and a high speed data reconstruction unit. Furthermore, a demo prototype has been built for experimentation.