Time-division multiplexing of large serial fiber-optic Bragg grating sensor arrays

Time-division multiplexing is a promising method for the interrogation of f iber-optic Bragg grating sensors arrays for measurement of strain and tempe rature. We examine the performance of these systems to determine the parame ters for high-sensitivity, low-cross-talk operation, It is shown that the p erformance can be greatly improved by use of a short time resolution in the demultiplexing process. We propose a new method of demultiplexing with an electro-optic modulator to read out the sensor pulses by gating the signal with 400-ps resolution. The system is demonstrated experimentally to provid e 0.15-mu epsilon/root Hz strain resolution in a;SO-Hz bandwidth within a f ull-scale range of 8000 mu epsilon. The system parameters are capable of ha ndling at least 50 time-addressed sensors on a single fiber. (C) 2001 Optic al Society of America.