Sometimes it is necessary to know the longitudinal surface, or bulk distribution pattern of certain physical quantities, e.g., to find the distribution of temperature and (or) mechanical stresses on the surface of buildings, bridges, dams, large reservoirs, aircraft, mobile platforms, ships, etc.; or to find the temperature distribution of electric power transformers, generators, reactors, in industrial process control systems, or in fire protection systems. Such problems can be solved with the aid of distributed optical fiber sensors (OFSs) [i, 2]. Block diagrams of distributed OFSs are shown in Fig. i, where L is a laser, OM is an optical modulator, PD is a photodetector, PU is a processing unit, D is a display, HFO is a high-frequency oscillator, LCFG is a linear variable frequency generator, P is a polarizer, and A is an analyzer.