Indirect comparison of the absolute LMR-Tunisia trap pyroelectric detector with the INM-France cryogenic absolute radiometer at 632.8 nm

A trap pyroelectric detector has been developed at the “Laboratoire de Métrologie des Rayonnements (Radiation Metrology Laboratory), LMR” to serve as a Tunisian standard for optical power measurements in the visible and infrared spectral range. This trap detector was indirectly compared with the cryogenic absolute radiometer of the “Institut National de Métrologie (National Institute of Metrology), INM-France” using a silicon photodiode. This comparison was performed at 632.8 nm and at a radiant power level of 350 μW. If the silicon photodiode is assumed to be stable with time, then the two radiometers of different design have been shown to agree to 3 × 10−3 with an uncertainty of 5 × 10−3 at the 1σ level.