| 摘要 |
PURPOSE:To output stable light signals even if the light signals varying in light intensity are switched by having light signal amplifying means which amplify the inputted light signals to prescribed intensity and outputs these signals and a light signal switching means which is connected to the output side of the plural light signal amplifying means and switches the light signals amplified to the prescribed intensity. CONSTITUTION:An input terminal 1 is connected via a signal line 110 to an optical amplifier 3 and an input terminal 2 is connected via a signal line 120 to an optical amplifier 4. The optical amplifiers 3 and 4 are signal intensity correcting circuits. The optical amplifier 3 is connected via a signal line 130 and the optical amplifier 4 is connected via a signal line 140, respectively to the input terminal of an optical switch 5, which outputs the light signal amplified to the specified intensity. The optical switch 5 is a switching circuit which outputs either of the light signals inputted from the signal lines 130 and 140. This circuit outputs the selected light signal via a signal line 150 to an output terminal 6. The input signal lights are adjusted to the same specified intensity by the optical amplifiers 3 and 4 and, therefore, even if the optical switch 5 switches the routes of the light signals at the time TA point, the output signal light having the stable light intensity of the light signal 105 is supplied. |
