This EURAMET European Metrology Programme for Innovation and Research (EMPIR) project 18SIB10 chipS·CALe is focused on developing a more robust linkage to the revised SI candela for optical power measurements. An improved and simplified traceability chain is vitally important for spectrally resolved measurements in photonics across industry and science. Using today’s methods, the uncertainty on measurements of optical quantities is limited by the properties and insufficient stability of current silicon transfer standard detectors, as well as costs of operation and required expertise for use. The novel combination of two independent primary standard detectors: a solid-state predictable quantum efficient detector (PQED) and a cryogenic electrical substitution radiometer (ESR) will be used to create a robust link to the revised SI by measuring the fundamental constant ratio e/h. The novel packaging of the two standards could also facilitate improved dissemination of optical quantities particularly where a primary standard needs to be used in challenging non-NMI environments, generating for the first time an “NMI-on-a-chip” for optical power measurements.