Patent attributes
An interrogation system includes lasers and an optical filtering device. The lasers include a primary set of lasers coupled to a primary multiplexer for generating primary light signals and a secondary set of lasers coupled to a secondary multiplexer for generating secondary light signals. The primary set of lasers may generate light signals having a first set of overlapping wavelengths and the secondary set of lasers may generate light signals having a second set of overlapping wavelengths. The optical filtering device may route the primary light signal and the secondary light signal to an optical fiber sensing cable positioned in a wellbore and receive reflection signals corresponding to the primary light signal and the secondary light signal. The reflection signals corresponding to the secondary light signal may have a first wavelength range that matches a second wavelength range of the primary light signals.
