| 摘要 |
Optical amplification stage (1) for OTDR monitoring, comprising a first (2a) and a second optical signal path (2b), a first (3a) and a second optical amplifier (3b), a first optical coupler (4a) placed along the first optical signal path downstream the first optical amplifier, a second optical coupler (4b) placed along the second optical signal path downstream the second optical amplifier, an optical by-pass path (5) optically connecting the first and the second optical coupler, a first (11a) and a second optical reflector (11b) optically connected to respectively the first and second optical coupler, and an optical filter (10) placed along the optical by-pass path which has attenuation high on the whole WDM band and low at the OTDR wavelength(s). |
| 主权项 |
1. Optical amplification stage for OTDR monitoring, the optical amplification stage comprising
a first and a second optical signal path having respectively first and second direction of propagation of a respective first and second optical signal, the first and second direction of propagation being mutually opposite, a first and a second optical amplifier located along the first and second optical signal path respectively and having an optical amplification band, each of the first and second optical signal being a WDM signal occupying a WDM band comprised within the optical amplification band, a first optical coupler placed along the first optical signal path downstream the first optical amplifier with respect to the first direction of propagation, a second optical coupler placed along the second optical signal path downstream the second optical amplifier with respect to the second direction of propagation and an optical by-pass path optically connecting the first and the second optical coupler, each coupler having
a first and a second signal port belonging to the respective optical signal path, the first port facing the respective optical amplifier, anda first and second by-pass port, the first by-pass port belonging to the optical by-pass path, wherein the first by-pass port is the cross-port with respect to the second signal port,the optical amplification stage further comprising
a first and a second optical reflector optically connected to the second by-pass port of respectively the first and second optical coupler, and an optical filter placed along the optical by-pass path and having an attenuation greater than or equal to 25 dB over the entire WDM band, wherein the first and second reflector and the optical filter are structured so that the sum, in dB, of the attenuation of the optical filter at a first and second OTDR wavelengths, comprised within the amplification band and outside the WDM band, and of the optical power ratio of the optical radiation incident to each optical reflector to the radiation reflected thereby at the first and second OTDR wavelengths, is less than or equal to 20 dB. |
