Yuzhe Yin

Numerical investigation of a stress-gradient sampled Bragg grating for dispersion compensation applications in wavelength-division multiplexing systems

In this paper, stress-gradient sampled Bragg grating (SBG) has been studied for the first time. The stress gradient can produce both chirps in the grating period and the sampling period. The group delay of the stress-gradient SBG is different from that of the normal chirped SBG. Based on direct calculations, it shows that stress-gradient chirped SBG can compensate for fiber dispersion and dispersion slope simultaneously in wavelength-division multiplexing systems.

A novel method for fabricating apodized fiber Bragg gratings

Abstract In this paper, a new implementation of the double exposure method for fabricating apodized fiber Bragg gratings by controlling the parameters of rotation stage and the number of UV-shots is presented. As a result, the average refractive index is kept nearly constant along the Bragg grating, and various apodized fiber Bragg grating with high reflectivity and high side lobe suppression ratio have been fabricated in single-mode hydrogen-loaded photosensitive fiber . The achieved side-lobe suppression ratio is larger than 25 dB .

A novel simple measurement technique of equivalent chirp in the grating period of sampled Bragg grating

In this letter, based on the proposed concept of Moire sampled Bragg grating (SBG), the equivalent chirp rates of various Fourier orders in a sampled Bragg grating with chirp in the sampling period (CSP) is demonstrated for the first time via a simple novel experimental method using phase mask rotation and dual exposure technique. Difference between experimental data and calculated results is less than 9%.

Analytical expression and system simulation of eye opening penalty for chirped sampled Bragg grating dispersion compensator

Abstract This paper discusses the impairment of bandwidth cutoff and group delay jump effects to eye opening penalty of chirped sampled Bragg grating dispersion compensator at 10 and 40 Gb/s theoretically. Both analytical and numerical simulation results show that bandwidth cutoff effect is the main reason for deterioration of eye opening penalty, while group delay jump effect is negligible. Cascaded transmission simulations also show that bandwidth cutoff effect does not cause the penalty deterioration apparently when span number increases.

Apodization compensation of sampled Bragg grating by off-coherent zone second exposure

Numerical results show that only apodization compensation is necessary for apodized binary sampled Bragg grating, while sampling compensation is not necessary. A novel off-coherent zone preconditioning approach is proposed which does not require to remove the phase mask. Experiments demonstrate the apparent improvements in the quality of reflectivity and group delay spectrum.

Novel sampled grating apodization technique

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.

A novel apodization technique of variable mark-space ratio for fabricating sampled fiber Bragg gratings

In this paper a novel apodization technique using a combination of a phase mask with an amplitude mask of variable mark-space ratio for fabricating sampled Bragg gratings is presented. By this technique it needs only single exposure process instead of double exposure in usual approaches to complete apodization and its compensation in the 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.

Stress-gradient sampled Bragg grating with a chirp in sampling period

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.