| 摘要 |
PROBLEM TO BE SOLVED: To provide a branched optical sweep detecting device and a WDM optical signal spectrum monitoring device which are capable of monitoring the spectrum of a WDM(wavelength division multiple) optical signal at high speed and which can be constituted compactly and with low loss and at a low cost. SOLUTION: In this device, a thin film heater 31 is coated on the optical coupler 12 of a lower part optical waveguide 10 and an upper part optical waveguide 11 and heater electrodes 32 and 33 are connected to both ends of the heater 31. Moreover, a diffraction grating is provided in the coupler part 12. When the current made to flow through the heater electrodes 32 and 33 is varied, the heating temperature of the coupler part 12 is changed and, in accordance with this, the wavelength of an optical signal to be branched from the coupler part 12 can be swept. Then, an optical spectrum can be obtained by converting the branched optical signal into an electric signal with a photoreceiving element 22 and, moreover, by converting this into optical power. Since the wavelength of the optical signal to be branched can be swept only by changing the current made to flow through the heater 31, the spectrum of the WDM optical signal is obtained at high speed. |
