| 摘要 |
PURPOSE:To form an optical switch with high stability by providing feedback so that light intensity or its ratio is constant. CONSTITUTION:The optical switch S inputs input light Li from its input terminal and outputs output light beams L01 and L02 from its output terminals by switching operation. The intensities of the output light beams L01 and L02 or intensity ratio of the both is detected and a control part C controls a control signal (a) and a driving signal (b) on the basis of the detection result to input both controlled signals (a) and (b) to the optical switch S. Then, the optical switch S is put in switching operation with the driving signal (b) and the amount of light loss generated in the switch S is controlled with the control signal (a). Thus, the control is performed with the control signal (a) to make the light intensity or their ratio constant stably and accurately. |
