Blocking Of ISOCAM Filters

Blocking has been measured using auxiliary wide band pass filters without overlap with the filters of the camera. Results of measurements with an InSb detector on the SW filters are presented in Table , and results of measurements with an InSb detector (m) and a pyroelectric detector (m) on the LW filters are presented in Table :

1. an empty entry comes from an overlap between the auxiliary filter and the camera filter
2. the error bar is a factor 10.

All the SW filters are completely blocked at lambda above 5.6 m, because of the cutoff of the detector response and at lambda below 1.2 m because of the Silicon lenses.

All the LW filters are completely blocked at lambda below 1.6 m because of the Germanium lenses. At lambda above 18 m, the situation is not as well quantified: there may be yet some residual (below 0.1 % of peak) long wavelength response of the detector due to impurities other than Ga atoms (uncomplete compensation), but the coatings of the lenses have a strong transmission roll off above 18 m.

  
Table: Blocking of the SW-Channel filters

  
Table: Blocking of the LW-Channel filters

  
Table: Summary of blocking of the ISOCAM filters