Operation and Software Features (Current version: 3.0)

The NanoHarp 250 can be used in various operation modes: 

Integration mode

Measurement of the accumulated events as a function of time, manually started, stopped manually or upon overflow or expiration of a chosen collection time. 512 curves with up to 262144 time channels. 

Oscilloscope mode

Repetitive measurement and on-line display, very useful for optical alignment. Flicker free histogram display updates and large rate meters for work in the distance.

Time-Resolved Emission Spectra (TRES)

An optional hardware and software add-on permits a monochromator to be controlled from within the NanoHarp 250 software, allowing automated measurement of Time-Resolved Emission Spectra. This mode drives a monochromator via a stepper motor for collection of spectrally resolved lifetime histograms. Data is collected as in standard Integration Mode and saved in different blocks of memory for each wavelength. Four different monochromator types are currently supported: Sciencetech 9030, Sciencetech 9055, Acton Research SP-2155 and Acton Research SP-275.

Software Overview

The NanoHarp 250 software allows the control of all measurement parameters provided by the NanoHarp 250 board. Both input triggers are programmable for a variety of signal types. All functions of the system are controlled by a Windows based software interface for all recent platforms from Windows, i.e. Windows 2000/XP/Vista/7. The software provides functions such as the setting of measurement parameters, display of measurement results, loading and saving of measurement parameters and measurement curves. Important measurement characteristics such as count rate, count maximum and position, and histogram width (FWHM) are displayed continuously. An automatic setup function adjusts the system to an initial optimum display range setting for the histogram. A comprehensive online help function shortens the user's learning curve. Software upgrades for extended functionality will be available with further product development.

A driver library (DLL) is available as an option for custom Windows program development, e.g. in LabVIEW, C++, Delphi or Visual Basic. Demo code is provided for an easy start. The libraries for Windows are API compatible, so that applications can easily be ported between the platforms.

The NanoHarp 250 permits the recording of milliseconds to sub-microsecond fluorescence lifetimes, extendable to nanosecond resolution with numerical reconvolution. For multi-exponential reconvolution the FluoFit software is an ideal tool. Measurement data from the NanoHarp 250 can be directly exported via the clipboard.

The figure below shows the results of a 10 second measurement with the NanoHarp 250. Here we excited the sample, Tris(2,2´-bipyridyl) rhutenium(II) chloride in distilled water, 1 µM concentration, with a LDH-P-C-440 laser diode head driven by PDL 800-B, externally triggered at 200 kHz. Luminescence was detected by a PMA 185 detector through a ScienceTech 9030 monochromator set to 620 nm with a 32 nm bandpass.

A typical fluorescence decay curve taken with the NanoHarp 250.