Identification and Sensing Experiments with Fiber-Bragg-grating-based Spectral Labels in Free-space Optics System

Yao-Tang Chang, Bo-Rong Huang, Chih-Lun Shao, Hsu-Chih Cheng
2018 Sensors and materials  
Keywords: fiber Bragg grating (FBG), fiber laser, spectral label identification/sensing, optical code division multiple access (OCDMA), free-space optics (FSO) system In this study, the spectral amplitude coding optical code division multiple access (SAC-OCDMA) is proposed for streaming data over a wireless transmission channel. A fiber-Bragggrating (FBG)-based parallel multiwavelength fiber laser is exploited as the light source, and a quasi-orthogonal M-sequence code as the signature address
more » ... ode is prewritten in the FBGbased encoder to create an identifiable spectral label. In free-space optics (FSO) systems, the experimental implementation of the proposed scheme verified that spectral labels resulting from an object's signals could preserve clear sensing signals in the transmitted encoded spectral label. After multiple spectral-label signals were passed through a real free-space channel in air at normal atmospheric temperatures, the results of the identification and sensing experiment showed that the autocorrelation (matched) and cross-correlation (unmatched) scenarios were tested to identify an individual object using the spectral-label decoder, and then unmatched noise interference was completely cancelled to sense successfully the object's signal using a balanced photodetector.
doi:10.18494/sam.2018.1935 fatcat:pnl47w2mqre6tej4dfgrtifx34