Measurement of distributed strain and temperature in a branched optical fiber network by use of brillouin optical time-domain reflectometry

A new scheme is proposed for sensing distributed strain and temperature in optical fibers. This scheme uses Brillouin scattering as the sensing mechanism and a branched optical fiber network as the sensing fibers. Brillouin optical time-domain reflectometry makes it possible to distinguish Brillouin-scattered light waves from different optical fiber branches in the network when the different Brillouin frequency shifts are assigned to each branch. The technical feasibility of this scheme is confirmed experimentally for a branched optical network composed of two branches connected to a trunk optical fiber.