In this paper, a low-cost repeaterless transmission system is demonstrated at 10Gbit/s using two Sampled Chirped fiber Bragg gratings (SCBG) to realize the dispersion compensation of 210km transmission over G.652 single-mode fiber (SSMF). The two SCBGs are used as dispersion management components to mitigate the damage caused by the pulse broadening effort before the receiver terminal. Non-return-to-zero (NRZ) modulation format is adopted and EDFAs as boost amplifier and pre-amplifiers in this system. Low-gain Raman amplifier is used to improve the signal noise ratio (SNR) at the end of the transmission fiber.
In this paper, with the superimposed technique a 4-channel chirped grating in a fiber for multi-channel dispersion compensation is been written. We have performed a dispersion compensation experiment with a system using a 10Gbit/s externally modulated laser. The experimental results show that measured BER of the all channels has the power penalty less than ±0.3dB when the grating is inserted through a circulator in front of the 100km transmission fiber.
A novel apodization technique is presented using a combination of a phase mask with an amplitude mask of variable mark-space ratio for fabricating sampled Bragg grating (SBG) for the first time. This technique only needs single exposure process instead of double exposure to complete apodization and apodization compensation in SBG fabrication. From our numerical simulation and experimental results, it can be seen that this technique is promising in changing reflection spectrum and reducing the ripple of group velocity delay of the sampled fiber Bragg gratings.
We demonstrate the simple relationship between the refractive index modulation, the chirp coefficient and the
reflectivity of the large chirped Bragg grating. When applying it to design the gain flattened filter, we can get almost the
same profile as the custom requests. At last, we propose the procedure using this method to write the gratings.
Numerical results show that only apodization compensation is necessary for apodized binary sampled Bragg grating, while sampling compensation is not necessary. A novel apodization compensation preconditioning approach is proposed. This process doesn't require the removal ofthe phase mask. We fabricate a 5 channels sampled Bragg grating with 0.25nm's bandwidth and —980ps/nm's dispersion. Dispersion compensation using the fabricated grating for standard single mode fiber 10Gb/s-80km transmission is demonstraded.
A new instrument to measure stokes vectors using an electro-drived polarization controller and a polarizer based on "TDM" is demonstrated. Using this instrument as well as data fitting and interleaving technique higher-order PMD is detailed.
A method is presented for the short period and large chirped fiber grating fabrication. The relation of grating reflectivity with chirp parameter is discussed and various reflectivity gratings have been achieved under different UV exposal conditions. At last, a broad bandwidth filter with a free filter zone is obtained.
A sampled Bragg grating (SBG) with a chirp in sampling period (CSP) is fabricated. When stress gradient is applied in the SBG with CSP, the characteristics of the spectrum response are different from that of a SBG without CSP. These experimental phenomena are consistent of the previous predictions. The stress-gradient SBG with CSP may be used as a tunable compensator for both dispersion and dispersion slope.
An effective method for photosensitizing fiber is presented in this paper. By adopting this method, the standard single- mode communication fibers are exposed to the flowing hydrogen gas at high temperature. We cannot only write the fiber gratings with different reflectivity, but also load hydrogen at different local position of fiber, which is very convenient for us to write the fiber gratings while the fiber is in fiber-based devices.