Laser Components' (Hudson, NH) COUNT® single photon counting modules (SPCM) achieve a quantum efficiency of over 70% in the red region and a significantly higher quantum efficiency in the blue spectral range. In addition, these modules are perfectly suited for measurements across the entire wavelength range from 400‑1000 nm. Laser Components has reduced the dead time of the COUNT® photon counters down to 42 ns — the previous dead time was 55 ns. This results in a maximum count rate of more than 23 MHz. In addition, the tolerance range of the supply voltage has increased. This allows the COUNT® module to react less sensitively to voltage peaks and small deviations in the supply voltage. The detectors are operated at 12 V.