| 摘要 |
An optical power monitoring device is provided with: an APD as a photodiode that converts the power of light to a current (Iapd); a resistor that is connected in parallel to the APD; a current mirror circuit that detects, as a first current value (I1), the value corresponding to the sum of the current (Irb) flowing through the resistor and the current (Iapd) flowing through the APD; and a control unit. The control unit stores in advance a value corresponding to the current flowing through the resistor as a second current value (I2), and determines the current (Iapd) flowing through the APD on the basis of the second current value (I2) and the first current value (I1) detected by the current mirror circuit. |
