SFDM/CWDM of fiber-optic Fizeau strain sensors

In this letter, a novel method for multiplexing a large number of fiber-optic Fizeau sensors using coarse wavelength-division multiplexing (CWDM) and spatial frequency-division multiplexing (SFDM) is proposed and demonstrated. A CWDM device is used to multiplex signals from different sensor channels occupying different wavelength regions divided by the CWDM. More than 10 Fizeau sensors arranged in a single channel can be multiplexed by using SFDM due to the long cavity length of the Fizeau sensor. The experimental results show that a strain accuracy of +/- 5 mu epsilon is achieved. As up to 100 sensors can be multiplexed simultaneously, this approach can improve the multiplexing capacity of fizeau strain sensors significantly.