Kaminow I P, Mammel W L, Weber H P
Appl Opt. 1974 Feb 1;13(2):396-405. doi: 10.1364/AO.13.000396.
Planar optical waveguides consisting of thin dielectric films with metal cladding have been investigated theoretically and experimentally. A computer program was devised to provide the phase and attenuation constants and wavefunctions for TE and TM modes in symmetric and asymmetric guides. Approximate expressions suitable for slide-rule calculation were also derived. Numerical results and illustrations are given for films of photoresist with Al, Ag, and Au cladding. Direct measurements of the attenuation and phase constants at 0.633 microm of numerous experimental waveguides are in reasonable agreement with theory. Attenuations <1 dB/cm, which is sufficiently small for application in devices, were measured. Calculated wavefunctions illustrate the mismatch of modes at transitions between unclad and metal-clad waveguides. Experimentally, we find substantial losses at such abrupt junctions. They can be overcome by simple tapered transitions.
由带有金属包层的薄介质膜构成的平面光波导已进行了理论和实验研究。设计了一个计算机程序来提供对称和非对称光波导中TE和TM模式的相位常数、衰减常数及波函数。还推导了适用于用计算尺计算的近似表达式。给出了以铝、银和金为包层的光刻胶薄膜的数值结果和图示。对众多实验光波导在0.633微米处的衰减常数和相位常数的直接测量结果与理论相当吻合。测量到的衰减小于1分贝/厘米，这对于器件应用来说足够小。计算得到的波函数说明了未包层和金属包层光波导之间过渡处模式的失配。在实验中，我们发现在这种突变结处有相当大的损耗。它们可以通过简单的渐变过渡来克服。
