| 摘要 |
PURPOSE:To obtain a multilayered filter for optical multiplexer/demultiplexer which is small-sized and has a high productivity and is easy to produce, by using a small area of only the surface area of optical beam transmission on a multilayered filter to constitute mutilayered filters. CONSTITUTION:A small area of only the surface area (sectional area approximately equal to an optical beam spot diameter) through which an optical beam having a wavelength lambda1+lambda2+-lambda4 is transmitted is used to constitute a multilayered filter as one body. The filter is cut along plural cutting lines in parallel with an incident light. These cutting lines are provided at intervals of a length slightly longer than the spot diameter, and plural filters are obtained by this cutting. When the light having a wavelength lambda is made incident at about 45 deg. to planes of these filter elements, a filter surrounded with a dotted line in Fig. is obtained. Several -10 one-body and small-sized multilayered filters are ob- tained from filters in Fig. to which the light having the wavelength lambda1+lambda2- is made incident. |
