低折射率实芯Bragg光纤传输特性研究

Study of the transmission characteristics of a Bragg fiber with low refractive index solid core

Bragg光纤是一种新型的光子晶体光纤,具有径向一维周期性结构。随着Bragg光纤研究的不断深入,国内外提出了具有各种不同结构的Bragg光纤,不再局限于空芯Bragg光纤。这就使Bragg光纤的研究内容更加丰富,也使更多新颖的传输特性成为可能。提出了一种低折射率实芯Bragg光纤,纤芯用SiO2作为材料,包层用折射率略高于SiO2的介质和SiO2交替产生周期性结构。使用渐进矩阵法对它的传输特性做了初步研究,发现在较宽的频带内有很好的单模传输特性,其泄漏损耗在10-3dB/km量级。

Bragg fiber is a new type of photonie crystal fiber with one - dimensional periodic structure. Now, a variety of Bragg fibers that are not limited to hollow core Brsgg fther have been studied. This makes novel characteristic transmission possible. In this paper, a Bragg fiber with a solid core of relatively low refractive index is proposed. The fiber is composed of SiO2 solid core that surrounded by a muhilayered cladding with an alternating layers of a higher refractive index dielectric and low refractive index SiO2. Using the Asymptotic Matrix Method, the fiber＇s transmission characteristics are analyzed. It is shown that there exists a broad band single - mode transmission window, and the leakage loss is less than 10^-3 dB/km.