Determination of the refractive indices of layers in a multilayer stack by a guided-wave technique

摘要

The m-lines technique is used to measure the refractive indices and thicknesses of layers embedded in a multilayer stack. The multilayer considered is deposited by ion plating. Its formula is silica－4H－L－4H－L－6H－air, where H and L denote Ta_(2)O_(5) and SiO_(2)λ/4 layers, respectively, with λ ＝ 514.5 nm. Measurements indicate that the refractive index of Ta_(2)O_(5) is 5 × 10~(-3) greater when the layer is close to air than when the layer is inside the coating and that the Ta_(2)O_(5) is slightly more birefringent.