  In this work, we report on a twin-core fiber sensor system that provides
improved spectral efficiency, allows for multiplexing and gives low level of
crosstalk. Pieces of the referred strongly coupled multicore fiber are used as
sensors in a laser cavity incorporating a pulsed semiconductor optical
amplifier (SOA). Each sensor has its unique cavity length and can be addressed
individually by electrically matching the periodic gating of the SOA to the
sensors cavity roundtrip time. The interrogator acts as a laser and provides a
narrow spectrum with high signal-to-noise ratio. Furthermore, it allows
distinguishing the response of individual sensors even in the case of
overlapping spectra. Potentially, the number of interrogated sensors can be
increased significantly, which is an appealing feature for multipoint sensing.
