三角形谱啁啾光纤光栅的制备及其在光纤无线单边带调制系统中的应用

Fabrication of triangular chirped fiber Bragg grating and its application in single-sideband modulation based radio over fiber system

本文涉及一种三角形谱啁啾光纤光栅的制备以及其在光纤无线(radio over fiber,RoF)单边带调制系统中的应用.基于相位掩模法和变速度折射率调制,实验制备了底部变化范围1.9nm、透射深度0—15dB的三角形谱啁啾光纤Bragg光栅,利用其透射谱具有较大负向斜边,研究了其在RoF系统中的应用.方案仅使用一个三角形谱光纤光栅,实现了以下两种功能1)双边带调制信号到单边带调制信号转换;2)降低信号的载波边带比(carrier-to-sideband ratio,CSR),提高接收灵敏度.并结合数值分析和仿真验证对方案进行了进一步的讨论.

In this work,we present an approach for fabricating triangular chirped fiber Bragg grating.Application of single-sideband modulation based radio over fiber system employing this grating is also analyzed.The proposed technology is based on phase mask and index modulation with changing velocity.A triangular fiber Bragg grating with 1.9 nm base width of transmission spectrum and 0—15 dB of transmission depth was fabricated experimentally.Due to the negative slope in transmission spectrum,the grating can be used in the radio over fiber system.In the proposed scheme,only a single grating is used to achieve two functions,i.e.OSSB ＋ C generation from DSB modulation signals,and reducing the carrier to sideband ratio of the generated signals.Numerical calculation and simulation ware performed and some discussions are given.