Optical directional coupler

Abstract

Abstract PURPOSE:To obtain an optical directional coupler for efficient light division, gathering, etc. CONSTITUTION:The optical directional coupler of this invention consists of fibers 1, 2, and 3 and an optical medium 4 such as a dielectric film. A refractive index n1 of the fiber 1, a refractive index n2 of the fiber 2, and a refractive index n4 of the optical medium 4 satisfy n2<n1 and n4<n1, and end faces of optical fibers 1 and 2 are polished obliquely at the same prescribed angle and are allowed to face each other through the optical medium 4 and are arranged on one line, and the light propagated in parallel along the axis in the fiber 1 is fully reflected by an interface 6 between the fiber 1 and the optical medium 4 and is inserted to the fiber 3, and the light propagated in parallel along the axis in the fiber 2 is not reflected by an interface 7 between the fiber 2 and the optical medium 4 and passes through the optical medium 4 and is inserted to the fiber 1. Thus, lights are divided and coupled with a small loss, and the constitution becomes simple.

Inventors

• 👤 Nobuo Kobata
• 👤 木幡　信夫

Bibliographic Details