| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical device which allows degradation of a light source to be predicted externally.SOLUTION: An optical device 10 comprises: a flat package 20; a metal ring 30; a cap; a surface-emitting laser array chip 60; and a light-receiving element 70. A part of a light flux emitted from the surface-emitting laser array chip 60 is reflected by a glass plate of the cap, and received by the light-receiving element 70 as a monitoring light flux. The light-receiving element 70 comprises: a first light-receiving unit 70a for receiving a center part of the monitoring light flux; and a second light-receiving unit 70b for receiving an outer peripheral part of the monitoring light flux. On the basis of an output of the first light-receiving unit 70a and an output of a second light-receiving unit 70b, a spread angle of the monitoring light flux can be determined. |
