三角形结构空芯PBG光子晶体光纤的带隙结构

The Bandgap Structure of Hollow-core Photonic Bandgap Guiding Fibers with Triangular Structure

用平面波法分析了三角形结构空芯PBG光子晶体光纤的带隙分布特性。结果表明:带隙宽度随着填充系数的增加而增大;而且随着包层孔中填充的介质的相对介电常数的增大,带隙宽度减小。在给定的归一化传播常数的条件下,带隙宽度有一从窄到宽再变窄的过程。适当增大包层基质折射率,在空气芯中导光的带隙数量增多,但包层基质折射率太大或太小都不利于空气中导光。

The bandgap distribution characteristic of hollow - core photonic bandgap guiding fibers with triangular structure is analyzed by plane waves method. The results indicate that the bandgaps increase with the increase of filling coefficient, when increasing the relative dielectric constant of the medium in rods of cladding, the width of bandgap is decrease. With the given normalized propagation constant, the width of bandgap has a variety from narrow to broad down again of narrow. While increasing the refractive index of the cladding suitably, the number of bandgap guiding in hollow - core are increasing but it is disbennifit if the the refractive index of the cladding is too large or too small.