Abstract
Chirped fiber Bragg grating is a promising approach for dispersion compensation in optical
fiber communication systems, since it’s passive optical component, fiber compatible and has low
insertion losses and low costs. Unapodized CFBG is fail to achieve the expected performance due to
high ripples in time delay response. Many apodization profiles are suggested to optimize grating
performance. Among them, hyperbolic tangent (tanh) apodization profile result in overall superior
performance. In this work, the reflection spectrum of CFBG is solved by numerical solution of
Reccati differential equation. Results show that, the characteristics of the tanh apodized CFBG can
varied systematically according to an angular tanh apodization profile parameter called truncation
parameter (atr). By using this parameter the characteristics of the grating is assist in term of
limitations of full-wave half maximum reflection bandwidth and minimizing average time-delay
ripples for different truncation parameter values. Results show that for a given chirped parameter
value CFBG approach optimal performance at truncation parameter of 4. In optical communication
bandwidth of 0.5nm CFBG can compensate linear dispersion of 100 km of standard optical fiber
length, the required grating length is 10 cm. According to these results, the truncation parameter
must be chosen carefully in performance optimization of the hyperbolic tanh apodized chirped fiber
Bragg grating. |