Aspects of the present disclosure relate to detecting an optical signal and/or optical power in a ferrule-less optical fiber. In certain embodiments, one or more optical detectors are incorporated into an adapter that is configured to interface with a connectorized or non-connectorized ferrule-less optical fiber. The optical detector detects the presence or absence, and/or the optical power level, of the optical signal being transmitted through ferrule-less optical fiber and produces an electrical output representative of the detected optical signal.