Abstract: An illuminator for use with a variety of end use light emitting devices for administering light for therapy and/or observation of an infant. One of the end use emitting devices is a device to provide phototherapy to the infant and is prevented by the illuminator from emitting light that has not been filtered to select the desire spectrum of wavelengths for phototherapy. The illuminator prevents the introduction of a connector to the phototherapy device from being inserted to an operative, secured position unless the proper filter is in position to filter out all of the undesired wavelengths before the light radiation can reach the phototherapy end use emitting device. Other end use light emitting devices may, however, be used with the same illuminator and their connectors are readily inserted into the illuminator to receive light radiating from the illuminator to the end use light emitting device.