| 摘要 |
PURPOSE:To prevent the generation of stray light by providing a collimate lens holder with a collimate lens and the aperture of an elliptical opening where the directions of its mirror axis and major axis are the same as the elliptical parallel luminous flux emitted from the lens. CONSTITUTION:A collimate lens 2 which is a single lens and whose focal distance is (f) is fixed in a collimate lens holder 7 and the elliptical parallel luminous flux where the minor axis of its sectional shape is (a) and its major axis is (b) is emitted from the lens 2. Next, the aperture having the elliptical opening whose minor axis is (p) and major axis is (q) whose directions are the same as the short axis (a) and the major axis (b) is integrally formed on the emitting side of the holder 7. Consequently, even when a radiation angle on the chip joint direction parallel side of a semiconductor laser is larger than the standard, the luminous flux to be made incident on an optical element is limited by the aperture. Thus, the generation of the stray light can be prevented and an excellent optical head can be obtained without increasing the number of parts and using a large-aperture beam shaping means. |
