A cascaded FBG scheme based OQPSK/DPSK modulation for chromatic dispersion compensation

Abstract

The aim of this study is to present a proposed chromatic dispersion compensation model for single mode optical fiber. The proposed model consists of 4-stages of cascaded identical linear chirped fiber Bragg grating (CFBG) in post-compensation connection scheme. It is based on differential phase shift keying modulation format. To evaluate the performance of the proposed model, a comparative study is conducted using offset quadrature phase shift keying modulation technique. This comparative study includes four cases with and without using CFBG. For system performance evaluation, a 10 Gbps wavelength division multiplexing link is simulated at a distance of 70 km under conventional operating parameters. Optisystem 7.0 has been used for simulation and evaluation process. Quality factor (Q-factor) and bit error rate (BER) are used as evaluation metrics. The proposed model shows the best performance in case of using CFBG compared to the other cases. A maximum Q-factor of 7.22, and a corresponding minimum BER of 2.59 × 10−13are obtained. The proposed system performance is enhanced by at least 53% as compared to related work.

Performance enhancement of optical communication system with cascaded FBGs of varying lengths

“…However, a cascaded CFBG structure formed with one LIC and one linearly decreased chirp (LDC) FBGs has given an FWHM of 1.56 nm is mentioned in [7]. On the other hand, a proposed four-stage cascaded FBG structure formed with hyperbolic tangent apodized FBGs has given better spectral characteristics (narrow FWHM of 0.07 nm and SLSR of 89.41 dB) than the structures in [18,20,40,41] is listed in the table as present work. The structure's performance is tested on a 105 km optical link operated at a bit rate of 12.5 Gbps, giving a BER of 9.53 × 10 −12 .…”

“…A comparative study of various recently reported cascaded structures and their performances on the optical transmission systems with the present work is reported in table 8. In all the listed cascaded structures [18,20,40,41], authors used the same type and same length of FBGs except the one presented in [7]. In the present work, we have used the same type of FBGs in the structure with varying lengths and tested its performance in the optical link.…”

“…The introduced transmission system is tested at a bit rate of 10 Gbps and has given a BER of 8.44 × 10 −11 . Further improvement in the BER to 2.59 × 10 −13 can be achieved using four identical types of LIC FBGs of the same lengths used in 70 km link operated with a bit rate of 10 Gbps along with the differential phase shift keying or DPSK modulation is presented in [41]. However, a cascaded CFBG structure formed with one LIC and one linearly decreased chirp (LDC) FBGs has given an FWHM of 1.56 nm is mentioned in [7].…”

Mode-Conversion-Based Chirped Bragg Gratings on Thin-Film Lithium Niobate

“…Chirped Bragg gratings have been extensively investigated for decades. In optical fibers, chirped Bragg gratings play an essential role in many applications, including dispersion control [1][2][3][4], a variety of sensing [5][6][7], mode-locked fiber lasers [8,9], microwave photonics [10,11], etc. In recent years, integrated photonic techniques, which use integrated optical components to generate, interconnect, and process signals, have become an inevitable trend.…”