title: Real-time fluorescence lifetime imaging system with a 32 x 32 0.13microm CMOS low dark-count single-photon avalanche diode array.
abstract: A compact real-time fluorescence lifetime imaging microscopy (FLIM) system based on an array of low dark count 0.13microm CMOS single-photon avalanche diodes (SPADs) is demonstrated. Fast background-insensitive fluorescence lifetime determination is achieved by use of a recently proposed algorithm called 'Integration for Extraction Method' (IEM) [J. Opt. Soc. Am. A 25, 1190 (2008)]. Here, IEM is modified for a wider resolvability range and implemented on the FPGA of the new SPAD array imager. We experimentally demonstrate that the dynamic range and accuracy of calculated lifetimes of this new camera is suitable for widefield FLIM applications by imaging a variety of test samples, including various standard fluorophores covering a lifetime range from 1.6ns to 16ns, microfluidic mixing of fluorophore solutions, and living fungal spores of Neurospora Crassa. The calculated lifetimes are in a good agreement with literature values. Real-time fluorescence lifetime imaging is also achieved, by performing parallel 32 x 16 lifetime calculations, realizing a compact and low-cost FLIM camera and promising for bigger detector arrays.
authors.affiliation: Institute for Integrated Micro and Nano Systems, Joint Research Institute for Signal & Image Processing/Integrated Systems/Energy/Civil and Environmental Engineering, School of Engineering, University of Edinburgh, The King's Buildings, Edinburgh EH9 3JL, Scotland, UK.
authors.forename: Day-Uei
authors.initials: DU
authors.lastname: Li
authors.forename: Jochen
authors.initials: J
authors.lastname: Arlt
authors.forename: Justin
authors.initials: J
authors.lastname: Richardson
authors.forename: Richard
authors.initials: R
authors.lastname: Walker
authors.forename: Alex
authors.initials: A
authors.lastname: Buts
authors.forename: David
authors.initials: D
authors.lastname: Stoppa
authors.forename: Edoardo
authors.initials: E
authors.lastname: Charbon
authors.forename: Robert
authors.initials: R
authors.lastname: Henderson
mesh_terms: D003199:Computer Systems; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D008856:Microscopy, Fluorescence / Q000295:instrumentation*; D017785:Photons; D015203:Reproducibility of Results; D012666:Semiconductors; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*