| 摘要 |
A semiconductor laser used as a light source of an optical module is susceptible to the return light from the lens surface. The problem has been conventionally solved by offsetting the optical axis of a lens and the optical axis of a semiconductor laser, but a high-precision and costly process for adjusting the positioning is required. An optical module and an optical unit, wherein the oscillation state of a semiconductor laser can be limited in the range of normal characteristics at a low cost, are provided by proposing a lens which eliminates the need for adjusting the positioning because there is little return light. As a first lens on which the light exiting a semiconductor laser impinges at first, a lens having an optical surface whose convex surface faces toward the semiconductor laser side is employed so that the light is diverged thus reducing the intensity of light returning to the semiconductor laser.
|
