| 摘要 |
PURPOSE:To improve the coupling efficiency by using a plane plate-shaped micro Fresnel lens as a condenser/collimator lens. CONSTITUTION:A micro Fresnel lens 3 formed on a transparent supporting cylinder body 2 is attached and fixed to the front end of an optical fiber 1. The spread light beams emitted from the optical fiber 1 are collimated by the Fresnel lens 3 and are emitted to the outside. Parallel light beams from the outside are condensed by the lens 3 and are made incident on the core of the optical fiber 1. A female mold of a preliminarily produced micro Fresnel lens is used to form this micro Fresnel lens 3(2) into one body with a transparent synthetic resin. For example, an electron beam resist is applied on a prescribed substrate, and a micro Fresnel lens pattern is drawn on the resist by electron beam drawing, and this resist is developed, and the remaining film resist pattern on the substrate is transferred to the substrate by dry etching to obtain the substrate as the female mold. Thus, efficient coupling is possible. |
