2009A&A...508..531N

A new extremely high speed photon-counting photometer, Iqueye, has been installed and tested at the New Technology Telescope, in La Silla. This instrument is the second prototype of a ``quantum'' photometer being developed for future Extremely Large Telescopes of 30-50m aperture. Iqueye divides the telescope aperture into four portions, each feeding a single photon avalanche diode. The counts from the four channels are collected by a time-to-digital converter board, where each photon is appropriately time-tagged. Owing to a rubidium oscillator and a GPS receiver, an absolute rms timing accuracy better than 0.5ns during one-hour observations is achieved. The system can sustain a count rate of up to 8MHz uninterruptedly for an entire night of observation. During five nights of observations, the system performed smoothly, and the observations of optical pulsar calibration targets provided excellent results.