Simultaneous multichannel carrier-suppressed return-to-zero to non-return-to-zero format conversion using a fiber Bragg grating

Abstract

A novel multichannel carrier-suppressed return-to-zero (CSRZ) to non-return-to-zero (NRZ) format conversion scheme based on a single custom-designed fiber Bragg grating (FBG) with comb spectra is proposed. The spectral response of each channel is designed according to the algebraic difference between the CSRZ and NRZ spectra outlines. The tailored group delays are introduced to minimize the maximum refractive index modulation. Numerical results show that four-channel 200-GHz-spaced CSRZ signals at 40 Gbits/s can be converted into NRZ signals with high Q-factor and wide-range robustness. It is shown that our proposed FBG is robust to deviations of bandwidth and central wavelength detuning. Another important merit of this scheme is that the pattern effects are efficiently reduced owing to the well-designed spectra response.

Fabrication of precise aperiodic multichannel fibre Bragg grating filters for spectral line suppression in hydrogenated standard telecommunications fibre

“…This trade-off is application specific, D4 is the design of choice for an application in signal conversion [21] from return to zero to non-return to zero as the wavelength RMSD error is around 50 pm. D3 on the other hand is more appropriate for OH emission line filtering as the channel strength is more critical in this application.…”

“…al. [21] demonstrated the application of multichannel grating for conversion of signals from return to zero to non-return to zero where the tolerance of error in the grating's bandwidth is 32 pm.…”