A new method for determining absolute spectral radiant power of ultraviolet and vacuum ultraviolet radiation

A spectral radiant power scale based on a synchrotron radiation has been established for ultraviolet and vacuum ultraviolet radiations. The absolute spectral radiant power of an under-test light source was determined by comparing the radiant power of the under-test source with that of the synchrotron radiation by using an optical system. Polarization state of synchrotron radiation is extremely different from that of the under-test source, and hence we introduced a special polarimeter for evaluating the polarization dependence of the optical system. We determined the absolute spectral radiant power of an under-test light source and evaluated the uncertainty of it.