Optical relay device, optical transmission system, and optical relay method

Abstract

An optical relay device (2) comprises: a coherent reception front end unit (110) that coherently detects an input optical signal to be inputted on the basis of locally emitted light; a coherent transmission front end unit (120) that coherently modulates the coherently detected signal on the basis of transmission light, and outputs a coherently modulated output optical signal; a light source (21) that outputs first light having a first wavelength; a light source (22) that outputs second light having a second wavelength; and a selection unit (130) that selects one of the first light and the second light, and outputs the selected light as locally emitted light or transmission light.

Claims

1. A coherent optical receiving front-end means that coherently detects the input optical signal based on local emission, A coherent optical transmission front-end means that coherently modulates the coherently detected signal based on transmitted light and outputs the coherently modulated output optical signal, A first light source that outputs first light of a first wavelength, A second light source that emits a second light of a second wavelength, A selection means for selecting either the first light or the second light and outputting the selected light as the station light emission or the transmission light, Automatic bias control means for controlling the bias voltage for coherent modulation of the coherent optical transmission front-end means, A storage means for storing the bias voltage before the light selected by the selection means is switched, Equipped with, The automatic bias control means stops the automatic bias control process before switching the light selected by the selection means, and after switching the light selected by the selection means, restarts the automatic bias control process using the bias voltage stored by the storage means. Optical relay device.

2. The selection means includes an optical switch that receives the first light and the second light and switches which light to output from among the input light. The optical relay device according to claim 1.

3. The aforementioned selection means is, A first variable attenuator that reduces the power of the first light by a set amount of attenuation, A second variable attenuator that reduces the power of the second light by a set amount of attenuation, The optical coupler includes a first light source that combines the first light source that passes through the first variable attenuator with the second light source that passes through the second variable attenuator. The optical relay device according to claim 1.

4. By controlling the attenuation amount of the first variable attenuator and the attenuation amount of the second variable attenuator, either the first light or the second light is output from the optical coupler. The optical relay device according to claim 3.

5. The first light source and the second light source are tunable light sources. When the selection means switches the light to be selected from the first light to the second light, it switches the light to be selected to the second light after the wavelength switching of the second light source is completed. The optical relay device according to any one of claims 1 to 4.

6. The first light source and the second light source are wavelength-fixed light sources. The optical relay device according to any one of claims 1 to 4.

7. The system comprises a plurality of light sources, including the first light source and the second light source, Each wavelength of the plurality of light sources corresponds to a wavelength usable in the optical transmission system including the optical relay device, The selection means selects one of the lights from the plurality of light sources and outputs the selected light as the local light emission or the transmitted light. The optical relay device according to claim 6.

8. The aforementioned selection means is, A first selection means that selects one of the lights from the plurality of light sources and outputs the selected light as the local light emission, A second selection means that selects one of the lights from the plurality of light sources and outputs the selected light as the transmitted light, The optical relay device according to claim 7.

9. An optical transmission system equipped with multiple optical relay devices, The aforementioned multiple optical relay devices are, A coherent optical receiving front-end means that coherently detects the input optical signal received from the preceding optical relay device based on local light emission, A coherent optical transmission front-end means that coherently modulates the coherently detected signal based on transmitted light and outputs the coherently modulated output optical signal to the next stage optical relay device, A first light source that outputs first light of a first wavelength, A second light source that emits a second light of a second wavelength, A selection means for selecting either the first light or the second light and outputting the selected light as the station light emission or the transmission light, Automatic bias control means for controlling the bias voltage for coherent modulation of the coherent optical transmission front-end means, A storage means for storing the bias voltage before the light selected by the selection means is switched, Equipped with, The automatic bias control means stops the automatic bias control process before switching the light selected by the selection means, and after switching the light selected by the selection means, restarts the automatic bias control process using the bias voltage stored by the storage means. Optical transmission system.

10. The input optical signal is coherently detected based on local emission, The coherently detected signal is coherently modulated based on the transmitted light, and the coherently modulated output light signal is output. Selecting either a first light of a first wavelength output from a first light source or a second light of a second wavelength output from a second light source, and outputting the selected light as the local light emission or the transmitted light, Controlling the bias voltage for the aforementioned coherent modulation, The bias voltage before switching the selected light is stored, Includes, Controlling the bias voltage includes stopping the automatic bias control process before switching the selected light, and restarting the automatic bias control process using the stored bias voltage after switching the selected light. Optical relay method.

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