title: Note: a 4 ns hardware photon correlator based on a general-purpose field-programmable gate array development board implemented in a compact setup for fluorescence correlation spectroscopy.
abstract: We present a fast hardware photon correlator implemented in a field-programmable gate array (FPGA) combined with a compact confocal fluorescence setup. The correlator has two independent units with a time resolution of 4 ns while utilizing less than 15% of a low-end FPGA. The device directly accepts transistor-transistor logic (TTL) signals from two photon counting detectors and calculates two auto- or cross-correlation curves in real time. Test measurements demonstrate that the performance of our correlator is comparable with the current generation of commercial devices. The sensitivity of the optical setup is identical or even superior to current commercial devices. The FPGA design and the optical setup both allow for a straightforward extension to multi-color applications. This inexpensive and compact solution with a very good performance can serve as a versatile platform for uses in education, applied sciences, and basic research.
authors.affiliation: Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, Universitätsstrasse 1, Geb. 26.32.02, 40225 Düsseldorf, Germany. stanislav.kalinin@uni-duesseldorf.de
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kalinin
authors.forename: Ralf
authors.initials: R
authors.lastname: Kühnemuth
authors.forename: Hayk
authors.initials: H
authors.lastname: Vardanyan
authors.forename: Claus A M
authors.initials: CA
authors.lastname: Seidel
mesh_terms: D017785:Photons; D012235:Rhodamines / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013997:Time Factors
chemical_list: D012235:Rhodamines; C049025:rhodamine 110