| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent an optical signal from being output before a wavelength of a laser beam output from a laser reaches a target wavelength. <P>SOLUTION: A drive circuit 6 controls the drive of a Peltier device 5 so that the wavelength of the laser beam output from the laser 4 reaches the target wavelength. After the wavelength of the laser beam reaches the target wavelength, an amplification control circuit 16 controls the amplification of an amplifier 14 so that an amplification amount reaches a reference amplification amount, and until the wavelength of the laser beam reaches the target wavelength, the amplification control circuit controls the amplification of the amplifier 14 so that the amplification amount is smaller than the reference amplification amount. Moreover, after the wavelength of the laser beam reaches the target wavelength, an attenuation control circuit 20 controls the attenuation of an optical attenuator 18 so that the intensity of the optical signal reaches reference intensity, and until the wavelength of the laser beam reaches the target wavelength, the attenuation control circuit controls the attenuation of the optical attenuator 18 so that the intensity of the optical signal is lower than reference intensity. <P>COPYRIGHT: (C)2011,JPO&INPIT |
