Optical cut-on filter for two different wavelength channel separation - is laminated with predetermined number of dielectric layers bounded by transparent medium

摘要

The optical cut-on filter is constructed in the form of a multi-layer system with a predetermined series of dielectric layers bounded on each side by a transparent substance so that this substance onone side approximates to the refractive index of the substance on the other side. The dimensions are such that the incident ray angle and layer structure are specified and then the refractive indices of the system are so determined, that the contours in the transmission range of the filter adopt the value zero. The choice of refractive indices can be determined precisely and with the use of a data processor zero positions of a contour or positions which are almost zero can be found.