Fiber Bragg grating (FBG) sensors are very useful and attractive for the measurement of strain and temperature. They have been developed not only for point sensing but also for distributed sensing. For measurement at multiple positions, multiplexing of FBG sensors is essential. We developed a novel multiplexing technique through intensity modulation of a light source. A light source was modulated in triangular form by an electro-optic modulator (EOM) at 1 MHz. Respective sensor signals located at different positions of the modulated source by delay lines and has different power levels. Simple signal processing demodulated them to independent sensor signals. One of the major advantages of this technique is the enhancement of signal-to-noise ratio (SNR) by a more powerful light source than pulsed one of conventional time division multiplexing (TDM). An 5-sensor system which had two Bragg-wavelengths, was demonstrated. It had good signal separation and good performance under 200 με.
