Optical time domain reflectometer for measuring optical return loss of optical fibre

摘要

The OTDR includes an arithmetic circuit (8). A known optical return loss of the optical fibre is set in the optical return loss input circuit (10) for the calibration purpose. The optical fibre for calibration is connected, and the optical return loss is measured. A computation circuit process the value measure from optical fibre and the known optical return loss to obtain the correction value of the receiver gain. Then, the measured optical fibre (4) is connected and the computation circuit integrates the measured waveform data of set section in gap and computes the optical return loss. The above referred correction value is multiplied and multiplexed. The optical return loss of the measured optical fibre is displayed.