Abstract: A method for testing an optical fiber, the method including transmitting, from a first light source of an optical power meter at a first time, a first light pulse in a first direction through an optical fiber; reflecting, by a fiber Bragg grating (FBG), the first light pulse in a second direction through the optical fiber, the second direction opposite the first direction; receiving, at the optical power meter, the reflected light pulse at a second time after the first time; determining, by circuitry associated with the optical power meter, a time delay between the first time and the second time; and measuring, by the circuitry, a length of the optical fiber based on the time delay.

Abstract: An apparatus, controller, and method for polarity detection, optical insertion loss measurement, optical power measurement, fiber length measurement, and optical fiber communication is provided, configured to transmit light from a light source; adjust a signal parameter of the light; compare an output optical signal parameter pattern of a cabling-under-test with a polarity pattern template; and determine the polarity of the cabling-under-test based at least on a best-fit of the output optical signal parameter pattern to the polarity pattern template.