| 摘要 |
PURPOSE:To easily obtain an optical couler which achieves high-efficiency coupling, by increasing the thickness of a light guide end part where a laser beam is photodetected, and decreasing the refractive index of the end part gradually in the traveling direction of the beam. CONSTITUTION:A laser beam emitted by a semiconductor laser 1 is made into a parallel laser beam through a cylindrical lens 2, and the beam is made incident to the end part 6 of a light guide as shown by an arrow. Since the end part 6 is increased in thickness, the collection of light is facilitated. The refractive index of the end part 6 is increased by deeply diffusing a diffusion material, and the refractive index is decreased successively from an optical coupling part 5 to a light guide 4. At the optical coupling part 5, the beam is directed to the part having a higher refractive index and condensed to relaize optical coupling with high efficiency. Further, the semiconductor laser 1 is coupled with a lens 2 by utilizing a V-shaped groove to facilitate the alignment of the axis of the laser to that of the light guide, thus obtaining an optical coupler with high efficiency. |
