贝耳电话实验室制得一张有趣的薄膜结构图片。假如把“搓板状”波纹结构加于薄膜光导管的表面,那末该装置就成为极限选择滤波器。光导管里传播的振荡模的半波长对应于波纹间距而实现反射。这时反射率为75%和3分贝的带宽为0.2毫微米。为了制造波纹结构,首先用在325毫微 Beal Phone Labs made an interesting film structure picture. If the “washboard” corrugated structure is added to the surface of the thin-film light pipe, then the device becomes the limit selection filter. The half-wavelength of the oscillation mode propagating in the light pipe corresponds to the spacing of the corrugations to achieve reflection. At this time, the reflectance is 75% and the bandwidth of 3 dB is 0.2 nm. To make the corrugated structure, it is used first at 325 nanometers