Tunable Super-Structured Fiber Bragg Gratings with Perfect Sequences Based on m-Sequence
; Ferreira, M.P.M.F.
; Gasparovic, M.G.
Journal of Electronic Science and Technology Vol. 15, Nº 4, pp. 358 - 363, December, 2017.
ISSN (print): 1674-862X
Journal Impact Factor: (in )
Digital Object Identifier: 10.11989/JEST.1674-862X.70912063
Recently, a tunable fiber Bragg grating (FBG) was developed by using stress-responsive colloidal crystals. In this paper, we have simulated the application of these nanoparticles into the super-structured fiber Bragg grating (SSFBG) written with perfect sequences derived from a short maximal-length sequence. A tunable SSFBG will be available to overcome the prohibitive temperature variation of the optical codecs. Nevertheless, we presented a method to implement coherent time spreading optical code-division multiple-access (OCDMA) where a unique code (or perfect sequence) can be reused and mixed with different wavelengths to obtain a tunable wavelength-division multiplexing (WDM) system. In order to maximize the binary throughput, we have selected a unique short maximal-length sequence composed of 7 chips that can be tuned with 7 different optical wavelengths. We found thousands of different tunable combinations that presented power contrast ratios (P/C) higher than 12 dB. When a WDM-OCDMA system used 2 different combinations simultaneously, the perfect binary detection with error correction codes was achieved successfully. The tunable SSFBG with colloidal crystals will be a simple and good alternative choice for fiber-to-the-home (FTTH) communications.