| 摘要 |
PURPOSE:To house many terminals by forming an optical local area circuit network of a star type by using an optical coupler having zero or nearly zero transmission coefft. of light between specific terminals. CONSTITUTION:An another waveguide 43 is installed between plural optical fibers facing each other, for example, upper photometric sides 2-1, 2-2-2-5, and lower photometric sides 3-1, 3-2-3-5 or waveguides facing each other, for example, 41-1, 41-2-41-5 on the upper side and 42-1, 42-2-42-5 on the lower side. At least one among a light shielding object, lens, prism and diagonal gap are provided in the position where the light between the specific input and output is prevented within these light guides. Part of the light generated from the specific port among N-pieces of the ports on the input side is thereby prevented from arriving to the specific port on the output side and arrives at the port on the other output side. The light generated from the other N-1 pieces of the ports on the input side arrives at N pieces of the ports on the output side. Since the transmission coefft. between the specific ports is decreased to zero or nearly zero, the optical local circuit network of the star type can be used. |
