| 摘要 |
PURPOSE:To provide an inexpensive and small sized optical isolator having easy constitution by providing a reflection film having a fine hole of the diameter smaller than the core diameter of an optical transmission body to which light is made incident to the one end of said optical transmission body. CONSTITUTION:The forward end of an optical fiber 100 is polished roughly perpendicularly to the optical axis of the optical fiber and a reflection preventing film 300 is attached to the end face thereof; further a reflection film 200 of Al having a fine hole 201 of about 8mu diameter is vapor deposited thereon. The fiber 100 is a focusing type fiber of 80mu core diameter as a core part 101 is shown by a broken line in the figure. Now, the light emitted from a semiconductor laser is restricted to about 2mu spot size by a lens, and is propagated in the core part 101 of the fiber 100 through the fine hole 201 provided to the film 200, whereby the coupling is accomplished with high efficiency. |
