HydraHarp 400

PicoQuant has launched a multichannel Picosecond Event Timer and Time-Correlated Single Photon Counting system (TCSPC) with USB interface.

The device is based on a novel time digitiser with one picosecond resolution, a processing rate of 12.5 million counts per second per channel, a very short dead time and an extremely low differential non-linearity.

The HydraHarp 400 has new features, including a modular design with up to four identical input channels and a common sync channel. All channels operate independently, but with a common crystal time base. Therefore, not only can TCSPC histograms for the measurement of fluorescence decays be obtained, but so too can picoseconds coincidence correlations across all channels. The latter is of great interest in single molecule work and quantum information processing research.

A timetagged data collection mode provides a stream of individual timing events to the host computer that can be processed and analysed with virtually unlimited flexibility, e.g. for photon burst detection, coincidence correlation or for combined measurement of fluorescence lifetime and fluorescence correlation spectroscopy (FCS).

The high timing resolution qualifies the system for use with high resolution detectors such as a Micro Channel Plate PMT (MCP-PMT). Overall time resolutions of 30ps can be achieved.

The HydraHarp 400 can also be used with all other common single photon detectors. Fully software controlled constant fraction discriminators (CFD) in all channels ensure precise and optimised timing. Accessories such as preamplifiers, attenuators and signal inverters allow the adaptation to virtually all signal sources. Sync/excitation sources can be as fast as 150MHz but even very slow sources can be used efficiently with 'multi-stop' acquisition.

The on-board histogramming mode is 32 bits deep and provides up to 65,536 time bins. This results in a count maximum of more than four billion counts per time bin and a total time span of 65ns. The base resolution of one ps can be binned in hardware, thereby providing longer histogram spans up to 65μs.

Time spans in time tagged mode are virtually unlimited. The timing of the individual channels can be shifted with respect to one another and with respect to the sync with picosecond resolution, simply through software control. This allows precise temporal alignment under the given experiment conditions without any need for physical adjustments of cable lengths or optical paths.

The system is designed as a USB 2.0 plug and play device, allowing control and data acquisition from a PC. The system hardware is reconfigurable by software for the implementation of different measurement modes and field upgrades. The system software runs on all recent Windows platforms including the x64 versions. It permits control of the hardware as well as convenient data handling and visualisation and supports control for monochromators, permitting the automated recording of time-resolved emission spectra (TRES). A programming library for custom software development will also be available.