Primary standard of optical power operating at room temperature Timo Dönsberg, Meelis Sildoja, Farshid Manoocheri, Mikko Merimaa, Leo Petroff and Erkki Ikonen EPJ Web of Conferences, 77 (2014) 00012 Published online: 19 August 2014 DOI: 10.1051/epjconf/20147700012