| 摘要 |
PURPOSE:To reduce the size and the cost of a high reliability type optical module by performing the deterioration detection of a semiconductor light emitting element and automatically driving to switch to a preliminary semiconductor light emitting element, and driving the element by one drive circuit. CONSTITUTION:When a semiconductor light emitting element 1-1 is deteriorated so that an input signal to a control circuit 7 becomes smaller than a value Vs, a signal for driving cooperation switches 8-1, 8-2 is generated at the output of the control circuit 7 to switch to connect a terminal a from 9-1 to 9-2 and a terminal B from 10-1 to 10-2, and second semiconductor light emitting element 2-1 is driven by the same drive circuit 6 when the emitting light intensity is reduced due to the deterioration of the initial element 1-1. The light emitted from one side of the element 1-2 is propagated in a waveguide 4-2 and 4-4 and fed in a direction of an arrow 5. The light emitted from the other side of the element 1-2 is photodetected by a photodetector 2-2, converted to an electric signal, and input to the control circuit 7. |
