Fast digital photon correlation system with high dynamic range

Abstract

Photon correlation has many applications in different scientific and technological areas. Correlation functions are calculated from the measured data in real time with dedicated circuitry. In this paper we present a correlator system for lag times from 6.25 ns to 3436 s. The extraordinary dynamic range of 10/sup 12/ is achieved with a multiple sampling time architecture. The key component of the correlator is the MTC72-chip used as a fast front end in the DSP-based system. The chip was implemented in 0.7 /spl mu/m CMOS standard cells using HDL-models and synthesis. The algorithmic concepts and the design considerations for the front end chip are outlined.