The presentation will discuss our latest efforts in developing a picowatt cryogenic thermal detector for use in measuring the emitted optical power from NRC quantum-dot single photon sources, and linking this measurement directly to the SI. I will also discuss the application of frequency-programmable Josephson voltage standards to the direct measurement of the electrical substitution power of the picowatt detector Co-sponsored by: National Research Council, Canada. Optonique. Speaker(s): Malcolm White, Virtual: https://events.vtools.ieee.org/m/385143