This volume focuses on Time-Correlated Single Photon Counting (TCSPC), a powerful tool allowing luminescence lifetime measurements to be made with high temporal resolution, even on single molecules. Combining spectrum and lifetime provides a “fingerprint” for identifying such molecules in the presence of a background. Used together with confocal detection, this permits single-molecule spectroscopy and microscopy in addition to ensemble measurements, opening up an enormous range of hot life science applications such as fluorescence lifetime imaging (FLIM) and measurement of Förster Resonant Energy Transfer (FRET) for the investigation of protein folding and interaction. Several technology-related chapters present both the basics and current state-of-the-art, in particular of TCSPC electronics, photon detectors and lasers. The remaining chapters cover a broad range of applications and methodologies for experiments and data analysis, including the life sciences, defect centers in diamonds, super-resolution microscopy, and optical tomography. The chapters detailing new options arising from the combination of classic TCSPC and fluorescence lifetime with methods based on intensity fluctuation represent a particularly unique highlight.

Time-correlated Single Photon Counting has been written in the hope that by relating the authors' experiences with a variety of different single photon counting systems, they may provide a useful service to users and potential users of this formidably sensitive technique. Of all the techniques available to obtain information on the rates of depopulation of excited electronic singlet states of molecular species, monitoring of fluorescence provides, in principle, the simplest and most direct measure of concentration. This volume comprises eight chapters, with the first focusing on the time dependence and applications of fluorescence. Succeeding chapters go on to discuss basic principles of the single photon counting lifetime measurement; light sources; photomultipliers; electronics; data analysis; nanosecond time-resolved emission spectroscopy; time dependence of fluorescence anisotropy. This book will be of interest to practitioners in the field of chemistry.

This book is a printed edition of the Special Issue "Photon-Counting Image Sensors" that was published in Sensors

In 1984 Desmond O’Connor and David Phillips published their comprehensive book „Time-correlated Single Photon Counting“. At that time time-correlated s- gle photon counting, or TCSPC, was used primarily to record fluorescence decay functions of dye solutions in cuvettes. From the beginning, TCSPC was an am- ingly sensitive and accurate technique with excellent time-resolution. However, acquisition times were relatively slow due to the low repetition rate of the light sources and the limited speed of the electronics of the 70s and early 80s. Moreover, TCSPC was intrinsically one-dimensional, i.e. limited to the recording of the wa- form of a periodic light signal. Even with these limitations, it was a wonderful te- nique. More than 20 years have elapsed, and electronics and laser techniques have made impressive progress. The number of transistors on a single chip has approximately doubled every 18 months, resulting in a more than 1,000-fold increase in compl- ity and speed. The repetition rate and power of pulsed light sources have increased by about the same factor.

Spectral, Photon Counting Computed Tomography is a comprehensive cover of the latest developments in the most prevalent imaging modality (x-ray computed tomography (CT)) in its latest incarnation: Spectral, Dual-Energy, and Photon Counting CT. Disadvantages of the conventional single-energy technique used by CT technology are that different materials cannot be distinguished and that the noise is larger. To address these problems, a novel spectral CT concept has been proposed. Spectral Dual-Energy CT (DE-CT) acquires two sets of spectral data, and Spectral Photon Counting CT (PC-CT) detects energy of x-ray photons to reveal additional material information of objects by using novel energy-sensitive, photon-counting detectors. The K-edge imaging may be a gateway for functional or molecular CT. The book covers detectors and electronics, image reconstruction methods, image quality assessments, a simulation tool, nanoparticle contrast agents, and clinical applications for spectral CT.

Photon counting is a unified name for the techniques using single-photon detection for accumulative measurements of the light flux, normally occurring under extremely low-light conditions. Nowadays, this approach can be applied to the wide variety of the radiation wavelengths, starting from X-ray and deep ultraviolet transitions and ending with far-infrared part of the spectrum. As a special tribute to the photon counting, the studies of cosmic microwave background radiation in astronomy, the experiments with muon detection, and the large-scale fundamental experiments on the nature of matter should be noted. The book provides readers with an overview on the fundamentals and state-of-the-art applications of photon counting technique in the applied science and everyday life.

This book first provides readers with an introduction to the underlying physics and state-of-the-art application of photon counting detectors for X-ray imaging. The authors explain that a photon-counting imaging detector can realize quantitative analysis because the detector can derive X-ray attenuation information based on the analysis of intensity changes of individual X-ray. To realize this analysis, it is important to consider the physics of an object and detector material. In this book, the authors introduce a novel analytical procedure to create quantitative X-ray images for medical diagnosis.