Walsh Hadamard Code and Wavelength Division Multiplexing Designed and Implemented Using Array FBGs

Abstract

Array fiber Bragg grating (AFBGs) was produced using an advanced fabrication technique to write many fibers Bragg gratings (FBGs) in a single strand of optical fiber without any splicing points. AFBG was used to assign a unique signature code for each user in a multiple access technique such as spectral amplitude encoding, optical code division, and multiple access (SAE-OCDMA). A number of bits have been assigned to the signature code including zero bits or one bits. Thus, by using FBG, the zeros bits can be achieved. Then, Walsh Hadamard (WH) code represents one of the smart encoding techniques that can be implemented by AFBGs. In addition, AFBG was applied to isolate the accompanying wavelength of the multiplexed signal. Likewise, AFBG was used to implement wavelength division multiplexing (WDM). Therefore, SAE can be improved by using AFBG. As a result, the code words (1 0 1 0), (1 1 0 0) and (1 0 0 1) for users 1, 2 and 3, respectively, are assigned by using AFBGs. The proposed experimental results are presented using a super luminescent diode (SLD), coupler, AFBGs, optical circulator, and fiber Bragg grating analyzer (FBGA). The proposed simulation results are presented using commercial software OptiGrating version 4.2 and OptiSystemTM version 7.0 from Optiwave.