Fast Readout High Performance Optical Detectors

The participants will investigate and promote detector developments for use in astrophysical contexts. Astrophysical detectors usually operate at low light levels, and thus have every high demands on quantum efficiency and low noise. This is particularly important if fast readout and short integration times are needed. The scientific aim is to explore astrophysical phenomena that involve very fast temporal evolution. The participants aim to develop common techniques for the wide range of field sizes and temporal resolutions required. A related, more technical application, aims at obtaining observations for brief periods of time when seeing-induced wavefront errors are negligible and diffraction limited images with large isoplanatic fields result. There are some similarities to the development of wavefront sensing at high speeds, required if seeing-induced distortions of incoming waves are to be corrected by deformable mirrors. The two applications meet at the low temporal frequency end (millisec) of JRA3 and the high-frequency end of JRA2.

This initiative involves fast imaging in the milli-sec regime, used for direct imaging as well as wavefront-sensing, and high time resolution astrophysics on sub-millisecond timescales.

There are common lines of research:

• evaluation, optimization, integration, and tests of state-of-the-art photon detectors,
• development of front-end-electronics and controllers which maximize speed and minimize noise,
• development of data handling software to exploit the data products to their fullest extent,
•develop the breadboard instrumentation to integrate systems for full quality control.

The activity will combine these different lines of research and development of sensor systems for studies of very high time resolution, based on the three most promising detector concepts: L3-CCDs, PN sensors, and Avalance PhotoDiode (APD) arrays.

The Chair of the Fast Readout High Performance Optical Detectors Joint Research Activity is H Spruit (MPA): henk @

For a PDF file copy of S Wagner's presentation of this Research Activity to the OPTICON I3 Board meeting in Ghent 1 - 2 April 2004, click here:

JRA3: Fast Detectors for Astronomy