单模光纤声光滤波器带宽特性的研究

Study on Bandwidth Characteristics of AOTF Based on Single Mode Fibers

研究了基于匹配包层 (MC)、色散位移 (DS)和色散补偿 (DC)单模光纤的声光滤波器的带宽特性。研究结果表明利用具有比较强的波导色散的光纤可以实现窄带声光滤波器。为了描述光纤的色散特性与滤波器带宽的关系 ,定义了一个新的表征光纤色散特性的参数 N并提出了通过测量光纤声光滤波器峰值波长调谐度来测量色散参数N的新方法。采用商用DC光纤在实验上实现了带宽为 0 5 5nm的半高全宽 (FWHM)全光纤声光滤波器。

Acoustooptic tunable fibers (AOTF) based on MC (matched cladding), DS (dispersion shifted) and DC (dispersion compensation) fiber were studied. It is found that the fiber with large waveguide dispersion is a promising candidate to reduce the bandwidth of AOTF. In order to describe the relations between the fiber dispersion and the filters bandwidth, a dispersion parameter N is defined and its relation to the tuning rate of the fiber AOTF is derived. This allows one to estimate the dispersion properties of a fiber by using the more easily measurable parameter of tuning rate. Experimentally, as narrow as 0.55 nm of FWHM bandwidth was demonstrated on commercially available DC fiber.