Abstract

Optical time-domain reflectometers (OTDR) are commonly used for the characterization and fault location of optical fiber transmission systems.^1–2 The dynamic range of current standard 1.55 µm OTDRs is 25−30 dB with a spatial resolution of 100 m. This is achieved by using a laser diode (LD) as a light source and a direct-detection technique. Here, the LD transmits probe pulses with a peak power of several tens of mW and a pulse width of 1 µ s. However, we must develop improved OTDRs to complement the extension in the optical transmission span realized through the use of erbium-doped fiber amplifiers (EDFA).³

© 2002 Optical Society of America