Instrument

OPTIMA ( Optical Pulsar TIMing Analyzer) is a high-speed photoncounter which is used to measure interesting objects, especially pulsars with high time resolution (10^-6 s) and high sensitivity.

As most of the objects targeted by OPTIMA are very weak optical emitters, it is mandatory to isolate the source flux as good as possible from the surrounding background sky, to achieve a useable signal to noise ratio. This is done by the use of optical fibers, whose diameters are matched to the expected seeing conditions and focal scale of the used telescope. As particularly the seeing conditions cannot be predicted precisely and might even change during the night, OPTIMA uses a hexagonal packed array of seven fibers. Each single fiber leads to a separate channel of the detector system i.e. seven avalanche photodiode detectors (APDs).

A detailed description is available in Kanbach und Straubmeier (2002) and in Kanbach et al. (2008). New developments include the possibility to measure with high time resolution also the polarisation of objects (OPTIMA photo-polarimeter (Kellner (2002), Kanbach et al. (2003) , Mühlegger, M. (2006)) and spectral colors in several bands simultaneously.