|Thesis abstract: |
In recent years the analysis of very weak and fast light signals has become more and more important in different fields of science: from medicine (Diffused Optical Tomography) to Biology (Fluorescence Lifetime Imaging Microscopy) up to Chemistry (Scanning Laser Microscopy). In this framework a very accurate technique, which is called Time-Correlated Single Photon Counting (TCSPC), has been playing a key role. It consists in a periodic stimulation of a sample through an optical source followed by the detection of the light emitted by the latter with a single photon detector. With the evolution of modern application of TCSPC, like Laser Scanning Microscopy which allows to analyze the interaction between proteins in a compound, the need for high speed multichannel systems, i.e. systems with a high number of both detectors and acquisition channels, has grown. In this way it is possible to reduce the measurement time by performing multiple measurements in parallel which can differ for parameters like wavelength or detector position. State of art TCSPC systems are basically divided in two categories: high parallelism (several thousands of channels) with low performance and high performance but with low number of channels (up to eight). The aim of this project is to develop multichannel systems with a high number of parallel channels with performances comparable with the ones of the best state of art systems, i.e. temporal resolution of 10 picoseconds and few percent of differential non linearity. These systems will integrate a custom SPAD array due to their high performance. If the system managed several thousand of SPAD in parallel, with an equal number of timing channels, the power consumption would be very high and also the managing of the data rate would be an issue. For that reason a smart router will be investigated in order to manage a SPAD array with a low number of acquisition channels. The main targets of this research project are three: the development of acquisition systems with inner picosecond resolution to be connected to SPAD arrays, the development of high throughput communication systems for data transfer and the interface between dedicated integrated electronics and SPAD arrays.