ROF系统中基于NLCFBG的可调色散补偿方法

Tunable dispersion compensation method based on NLCFBG in ROF systems

在光载无线(ROF)系统中,光纤的色散会导致系统中传输的信号产生畸变,更为严重的是会引起系统输出射频信号的幅度随光纤传输的距离发生周期性的起伏变化,从而严重限制系统的性能。基于非线性啁啾光栅(NLCFBG)的可调色散补偿方法,为克服光载无线系统中光纤色散的影响提供了一个简便、灵活的方案。首先采用计算机仿真对该方案在光载无线系统中进行色散补偿的应用作了全面的分析,然后研究了光栅的群时延抖动对色散补偿性能的影响。研究结果表明,基于非线性啁啾光栅的色散补偿方案能对光载无线系统中双边带调制的射频信号传输进行有效的可调色散补偿,但光栅的群时延抖动会对传输的信号造成一定损伤,需要在光栅的设计、制作过程中进行优化。

In a radio over fiber （ ROF） system, fiber dispersion causes signal distortion and periodical fluctuation of the output signal amplitude in the system, which greatly limits the system performance. The tunable dispersion compensation method based on nonlinear chirped fiber Bragg gratings （ NLCFBG） can tackle this problem in a con-venient and flexible manner. In this paper, the performance of this method was firstly verified, and then the impact of group delay ripple was thoroughly analyzed through computer simulation. The results show that the NLCFBG based dispersion compensation method can reduce the transmission dispersion of double sideband modulation radio frequency（RF） signals in radio over fiber（ROF） system, while the group delay ripple of a NLCFBG can induce signal impairment, which need to be considered in the optimized design and fabrication of the NLCFBG.