Operational extra space measurement equipment and operational extra space measuring method null of

摘要

PURPOSE: To measure the operational margin of an optical repeater corresponding to intersymbol interference quantity by providing a wavelength control means for measuring the wavelength of main signal light and for setting the wavelength of intersymbol interference noise light, based on the wavelength of main signal light. CONSTITUTION: This device is constituted by adding a wavelength discrimination circuit 21 for discriminating the wavelength of main signal light and a wavelength control circuit 22 for controlling the wavelength of intersymbol interference noise light corresponding to the wavelength of main signal light to conventional configuration. At the wavelength control circuit 22, the loss amount of a wavelength dependency loss element is found in comparison with light intensity detected by a light intensity detector 16, the wavelength corresponding to that loss amount is created while referring to a data table, and the wavelength of main signal light is decided. Thus, the wavelength control circuit 22 sets the wavelength of intercode interference noise light, based on the wavelength of main signal light. Concerning the wavelength of intersymbol interference noise light, the amount of separation from main signal light is more than six times of the bit rate of main signal light and further, it is inside the band of an optical filter built in a receiver.