PURPOSE: To increase the efficiency of combination to an optical fiber, by reducing evenly the refractive index in the optical axis direction from an end toward the other end for a graded lens having the refractive index lowering from the center toward the outer circumference.
CONSTITUTION: The refractive index in the optical axis direction is evenly reduced from an end toward the other end for a graded lens 1 which has the refractive index lowering from the center toward the outer circumference. The end face of an optical fiber 2 is adhered to an end face having a low refractive index. A beam 4 which is made incident from an end face 2 of the lens 1 with an incident angle θ2 has its amplitude being gradually reduced to be made incident to a core 5 of the fiber 2 with an incident angle θ1 smaller than the angle θ2. Thus the efficiency of combination is increased between a graded lens and an optical fiber.
ONO KOUZOU
NISHIWAKI YOSHIKAZU
TSUNO KOUICHI
| JPS5543538A | 1980-03-27 | |||
| JPS5233545A | 1977-03-14 |