质子交换Y分支光波导弯曲损耗研究

Bend Loss of Annealed Proton-Exchanged Y-Branch LiNbO_3 Optical Waveguides

对采用退火质子交换技术(APE)制备的具有正弦型弯曲和余弦型弯曲两种不同的S型弯曲的Y分支光波导,利用宽角有限差分光束传播法,就过渡区长度、波导表面折射率增量、掩模版开口宽度等对波导弯曲损耗的影响进行了研究。结果表明,两种S弯曲下的Y分支波导的弯曲损耗,随波导结构参数的变化基本上是相同的,但二者的表现并不完全一致。数值计算结果为相应波导器件的设计和制备提供了一定的参考。

Annealed proton-exchanged （APE） LiNbO3 optical waveguides are currently used in many integrated optic devices. Using the wide angle finite difference beam propagation method （FD-BPM）, the influences of the waveguide parameters, such as the transition length, the variation of the surface index and the width of mask opening, on the bend loss of the Y-branch optical waveguides with two different S-shaped bend fabricated by APE technology are analyzed. The results show that the dependence of bend loss on the waveguides parameters is analogous for the Y-branch waveguide with two kinds of S-shaped bend. But they are not precisely consistent with each other. The numerical results are useful for the design and fabrication of the associated optical waveguide devices.