| 摘要 |
<P>PROBLEM TO BE SOLVED: To speed up switching, to decrease a circuit scale, and to increase a dynamic range of a branching light monitor, relating to a control circuit for an acousto-optical tunable filter for dividing an optical signal of a selected wavelength. <P>SOLUTION: The control circuit comprises an RF signal generation circuit 2 for applying a high-frequency signal to AOTF 1, a branching light monitor circuit 3 for monitoring the optical signals branching from AOTF 1, and a signal processing circuit 4 for controlling the RF signal generation circuit 2; the RF signal generation circuit 2 is provided with a DDS 6 for generating a high-frequency signal of a frequency and an amplitude according to the setting information on the frequency, phase, and amplitude from the signal processing circuit, and a signal processing part 7 for multiplying the frequency of the high-frequency signal from the DDS 6; and the branching light monitor 3 is provided with a log amplifier 11 for current-voltage conversion for converting the current flowing through a photo diode 10 for inputting the branching light, and an A-D converter 14 for inputting the branching light monitoring signal to the signal processing circuit 4. <P>COPYRIGHT: (C)2004,JPO |
