OTDR Testing in OFC Projects: What EPC Teams Must Know

An Optical Time Domain Reflectometer (OTDR) is an instrument used to test the integrity of optical fibers. It injects pulses of light and measures the backscattered and reflected light to identify splice losses, connector losses, and fiber breaks.

Typical OFC project acceptance criteria: • Splice loss per joint: < 0.1 dB (fusion splice) • Connector loss: < 0.3 dB • Total link attenuation: per design budget • Event loss: < 0.3 dB (any event)

The OTDR trace shows distance on X-axis and signal level (dB) on Y-axis. Events appear as: (1) Steps down = loss at splice/connector. (2) Spikes up then down = reflection (connector/break). (3) End of fiber = sharp drop to noise floor. Each event is measured in dB loss.