A new type of optical-time-domain reflectometer (OTDR) has been demonstrated. It uses a semiconductor laser diode (LD) as both a pulse emitter and a photodetector. With a LD operating at 1.31 μm, a fault-location length for a single-mode optical fiber of about 20 km has been achieved by extrapolating the log-transformed OTDR slope to the background-noise level. This length has been extended to 25 km at a wavelength of 1.56 μm. Wavelength and polarization dependences of the LD's as photodetectors were also investigated. No polarization dependence was observed.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics