Springer Ser Fluoresc (2008) 5: 259–275 DOI 10.1007/4243_2008_048  Springer-Verlag Berlin Heidelberg Published online: 27 March 2008 Time-Resolved Fluorescence: Novel Technical Solutions Uwe Ortmann (✉) · Michael Wahl · Peter Kapusta PicoQuant GmbH, Rudower Chaussee 29, 12489 Berlin, Germany info@picoquant.com 1 Introduction ................................... 259 2 Excitation Sources ................................ 260 2.1 Picosecond Diode Lasers ............................ 260 2.2 Fibre Laser .................................... 262 2.3 Turn-key Ti:Sapphire Laser Systems ...................... 262 2.4 Light-Emitting Diodes .............................. 263 2.5 Example of the Use of LEDs in Spectroscopy ................. 263 3 Detectors ..................................... 264 4 TCSPC Electronics and “High Information Content” Data Formats .... 266 4.1 Fluorescence Lifetime Correlation Spectroscopy ............... 270 5 Conclusion .................................... 274 References ....................................... 274 Abstract Time-resolved techniques are more and more accepted as versatile and powerful tools for the investigation, analysis and online process control of chemical and biological processes. In the past, the common understanding was that the technique was compli- cated and complex. However, this has changed dramatically and technical advantages in the field of time-resolved studies are manifold. New laser materials and types have been developed that now ensure a turn-key operation; the measurement electronics have been improved and simplified and the detectors have also evolved into more sensitive, yet easier to handle, devices. Especially, simplifications and reduction of system cost have boosted the acceptance of time-resolved fluorescence techniques in routine laboratory work. In this contribution we would like to focus only on areas where large improve- ments have been made in the past. We will mainly focus on small and low-cost excitation sources, novel detector types and the use of modern data acquisition electronics that pre- serve the full photon information. Examples will briefly give some reference to the use of these novel techniques in the field of time-resolved spectroscopy. Keywords FLCS, fluorescence lifetime correlation spectroscopy · Gain switching · Pulsed diode lasers · SPAD · Time-resolved fluorescence · Time tagging · TTTR 1 Introduction Time-resolved fluorescence techniques are more and more accepted as ver- satile and powerful tools for the investigation, analysis and online process