SEMICONDUCTOR LIGHT EMITTING DEVICE AND APPLIED PRODUCT THEREOF

摘要

PURPOSE:To obtain a beam with a small beam width by a method wherein the light rays emitted from a light emitting element are made to converge through a lens and converted into a parallel beam through a second lens. CONSTITUTION:A semiconductor laser is used as a light emitting element 1 and GRIN (graded index) rod lenses of small aberration are employed as lenses 2 and 3. The light rays emitted from the element 1 are made to converge through the first lens 2. The second lens 3 is so specified to have a focal point at its end face. Here, the distance between the lenses 2 and 3 is so set as to be equal to the distance la from the right end face of the first lens 2 to the light converging point in order to make the light converging point of the first lens 2 coincident with the focal point of the lens 3.