| 摘要 |
PURPOSE:To separate and remove an unnecessary polarized light component and, at the same time, to improve the efficiency of optical coupling, by optically coupling a laser diode and plane of polarization maintaining optical fiber through module elements, so that a specific condition is satisfied. CONSTITUTION:A spherical lens 3 for laser diode, spherical lens 4 for optical fiber, and polarized light separating plate 5 are arranged in the order shown in the figure between a laser diode 1 and plane of polarization maintaining optical fiber 2. Optical axes of each module element 1, 2, 3, 4, and 5 coincide with their mechanical central axis 6. Moreover, of the module elements, the laser diode 1, optical fiber 2, and both spherical lenses 3 and 4 are constituted and arranged so as to satisfy equation I. As a result of this arrangement, a high efficiency of optical coupling is obtained and a laser light O which is made incident to the polarized light separating plate 5 is separated into polarized light components O1 and O2 and only the component O1 is made incident to the optical fiber 2. Therefore, an unnecessary polarized light component is separated and removed and, at the same time, the efficiency of optical coupling is improved. |
