| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact device capable of detecting even a focus error signal by integrally constituting a light receiving and element and a light emit ting element on one semiconductor substrate and providing a slantly arranged reflection body and a reflection body having a curved surface. SOLUTION: Light receiving and emitting elements are constituted on one semiconductor substrate 13. That is, a light emitting part is provided with a semiconductor laser element 14, a first reflection mirror 15 as a first reflection body and a second reflection mirror 16 as a second reflection body formed on the substrate 13. Moreover, a photodetector is constituted of first photodetectors 17 and second photodetectors 18 respectively formed at the surroundings of the reflection mirrors 15, 16 on the substrate 13. The reflection mirror 15 perpendicularly reflects the light beam L1 from the front plane of the element 14 upward and makes a return light incident on the first photodetectors 17. The reflection mirror 16 is formed on the slope having a curvature and which provided on the substrate 13 and reflects the light beam L2 from the backward of the element 14 upward and makes a reflected light incident on the phtodetectors 18. |
