| 摘要 |
PURPOSE:To decrease the effect of the reflected light, by having a curved incident surface of a focusing rod lens and securing the coincidence between the focal distance ratio between a condensing rod lens and a focusing rod lens and the ratio between the beam radius of an optical fiber and the radius of the geometrical means beam of a laser diode. CONSTITUTION:The light given from a laser diode 1 is connected to the core 5 of an optical fiber 4 via a condensing ball lens 2 and a focusing rod lens 3. The incident surface 7 of the lens 3 is curved, and accordingly the reflected beams on the surface 7 are not parallel to each other and not fused at a light emitting part of the laser as shown by the dotted lines. At the same time, an equation is satisfied, where the focal distances of the lenses 2 and 3 are set at f1 and f2 respectively, the horizontal and vertical beam waist radii of the active layer of the diode 1 are set W11 and W1, and the beam waist radius of the fiber 4 is set W0 respectively. |
