A novel approach utilizing optical SIK-DS-CDMA overcomes restrictions of traditional FBG sensor networks

Due to their variability Fibre Bragg Grating (FBG) sensors are introduced in a growing number of applications. Furthermore using their spectral selectivity and adjustable reflectivity these sensors are predestined for serial networking, whereby presently in most cases the addressing is realised by time division multiple access (TDMA) or wavelength division multiple access (WDMA). But these technologies have big disadvantages regarding the effective use of the prevailing resources time and wavelength, respectively. In this paper a new scheme capable of addressing a large number of FBGs in a single serial network is proposed and compared to TDMA and WDMA. Using all optical sequence inversion keyed (SIK) direct sequence (DS) code division multiple access (CDMA) it overcomes the restrictions handling the resources time and wavelength without loosing accuracy. A simulation with 20 FBGs in a spectral range of 2nm shows the abilities of this system, which can be build up with nearly the same components as TDMA systems.