HIGH-PERFORMANCE SINGLE-MODE OTDR USING COHERENT DETECTION AND FIBER AMPLIFIERS

A high performance single mode OTDR has been constructed at 1.55 µm using a DFB laser diode, laser diode pumped fibre amplifiers and a coherent detector, all suited to integration into a robust and portable instrument. A dynamic range of 33 dB has been attained with 1 µs launch pulses, 1 MHz receiver bandwidth and 10 integrations. This result represents an increase of about 13 dB in performance over the standard version of the OTDR using a laser diode as a light source. It is comparable to the best previously reported value attained using a high power glass laser and a cooled detector. © 1990, The Institution of Electrical Engineers. All rights reserved.