| 摘要 |
PURPOSE:To attain the precise and high-accuracy monitoring of laser beams by light receiving element by defining a light emitting element as a laser chip and a light receiving element by an electromagnetic shield. CONSTITUTION:A light receiving element 22 and a light emitting element 5 as a laser chip are shielded electromagnetically by an electromagnetic shield 4. A shield 4 is provided with a transparent body 9 for guiding the light emitted from the element 5 to the element 22. Even if a current flows in the element 5 when the device is used in a high-frequency region, an action of a magnetic field does not influence on the element 22 and magnetic coupling does not occur. Accordingly, the monitoring of laser beams by the element 22 can be done precisely with high accuracy. |
