The TimeHarp 260 is a compact, easy to use, Time-Correlated Single Photon Counting (TCSPC) and Multi-Channel Scaling (MCS) board for the PCIe interface. It is based in a custom TDC design that offers an ultrashort dead time even at high temporal resolutions. The board is available in two versions with either 25 ps (PICO module) or 1 ns (NANO module) base resolution.
Multiple input channels for highly flexible use
Each version of the TimeHarp 260 is available in different configurations with either one or two independent detection channels and an additional common sync input. All of them, including the sync input, can be used as independent timing channels for coincidence correlation experiments. Alternatively the common sync input can be used for TCSPC with fast excitation sources. The other input(s) can then be used as independent detector channels for TCSPC. In this case the TimeHarp 260 allows forward start-stop operation at the full repetition rate of mode locked lasers with stable repetition rate up to 100 MHz.
PICO module for high resolution TCSPC
The TimeHarp 260 PICO is designed for high timing resolution. With a digital resolution of 25 ps and a timing jitter <20 ps it is well matched to the timing resolution of the majority of common photon detectors. All input channels are equipped with software-adjustable Constant Fraction Discriminators (CFD) sensitive on the falling edge. The ultra short dead time of the TimeHarp 260 PICO of <25 ns per channel allows very high measurement rates. Along with the extremely low differential non-linearity of the instrument, excellent data quality can be obtained.
The histogramming time range of the TimeHarp 260 PICO can be extended up to seconds with an optional "long range mode". In this mode the base resolution of the board is switched to 2.5 ns and the dead time reduces to <1.5 ns. This permits to study dynamics from picoseconds up to seconds with just a single board.
NANO module for MCS and deadtime-free correlation
The TimeHarp 260 NANO is designed for ultimately short dead time at a moderate time resolution. Exactly like the PICO model it can be used for coincidence correlations across all inputs or for TCSPC with light source trigger connected to the sync input. Because of the short dead time and the long histogram range it is particularly suited for classical Multi Channel Scaler (MCS) applications. Software-adjustable discriminators and polarity switches allow the TimeHarp 260 NANO to be interfaced to a wide range of signal and trigger sources. The board's multi-stop capability allows efficient recording of long-lived fluorescence and luminescence decays up to the seconds time range with correspondingly slow excitation rates, yet at very high detector count rates.
Adjustable delay in each input channel
Each input channel has an internal adjustable delay with ±100 ns range at either 25 ps resolution (PICO model) or 1 ns resolution (NANO model). This unique feature eliminates the need for specially adapted cable lengths or cable delays for changes in experimental setup.
Time-tagged Time-resolved modes
A Time-tagged mode for recording of individual photon events with their arrival time on all channels allows the most sophisticated offline analysis of the photon dynamics. Time-Tagged Time-Resolved (TTTR) data can also be correlated in real-time for monitoring of FCS experiments at count rates up to 1.000.000 counts/sec. External marker signals can be used to synchronize the device with other hardware such as scanners, e.g., for Fluorescence Lifetime Imaging (FLIM).
Programmable trigger out
The TimeHarp 260 also features a trigger output, which can generate pulse periodes between 0.1 µs and 1.678 s, corresponding to repetition frequencies between 0.596 Hz and 10 MHz. This feature can e.g. be used to control external lasers.
Easy-to-use software or custom programming
The TimeHarp 260 software for Windows provides functions such as the setting of measurement parameters, display of results, loading and saving of measurement parameters and measurement curves. Important measurement characteristics such as count rate, count maximum, position and peak width are displayed continuously. A comprehensive online help function shortens the users' learning curve. A library for custom programming e.g. with LabVIEW is also available as an option. Software upgrades for extended functionality will be available with further product development.
Measurement data from the TimeHarp 260 can be analyzed by different software packages. For multi-exponential reconvolution the FluoFit software is an ideal tool. For the analysis of TTTR data (e.g. FLIM, FCS, FLCS, FRET, BIFL, etc.) the SymPhoTime 64 software suite is the tool of choice.