Abstract: Based on the principle of spontaneous parametric down conversion,a wide band correlated photon source is generated.Combined with traditional spectral irradiance measurement instruments,a new spectral irradiance measurement method based on correlated photons self-calibration is proposed.The spectral irradiance measurement principle and experimental system were introduced,and a study on the transfer chain of “channel quantum efficiency→spectral photon number rate→spectral power responsivity→spectral irradiance” was carried out.A radiation measurement model based on correlated photons self-calibration was established,and the uncertainty of spectral irradiance measurement was analyzed detailedly.Using a 488 nm laser beam passing through a collimated light source of an integrating sphere and collimator as the irradiance source,a comparative experiment between a correlated photon self-calibration spectral irradiance meter and a standard irradiance meter was conducted,and the preliminary verification showed that the consistency of the two measurement methods was better than 4.2 %.

Key words: Self-calibration, Spectral irradiance meter, Spectral irradiance, Measurement uncertainty