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.

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.

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.

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

The topics range from single molecule experiments in quantum optics and solid-state physics to analogous investigations in physical chemistry and biophysics.

Carl Wieman's contributions have had a major impact on defining the field of atomic physics as it exists today. His ground-breaking research has included precision laser spectroscopy; using lasers and atoms to provide important table-top tests of theories of elementary particle physics; the development of techniques to cool and trap atoms using laser light, particularly in inventing much simpler, less expensive ways to do this; the understanding of how atoms interact with one another and light at ultracold temperatures; and the creation of the first Bose-Einstein condensation in a dilute gas, and the study of the properties of this condensate. In recent years, he has also turned his attention to physics education and new methods and research in that area. This indispensable volume presents his collected papers, with annotations from the author, tracing his fascinating research path and providing valuable insight about the significance of the works.