Method and apparatus for monitoring optical signal-to-noise ratio (OSNR) using polarization-nulling method

摘要: The present invention relates to a method and apparatus for automatically monitoring an optical signal-to-noise ratio in which arbitrarily polarized signal including unpolarized ASE noise is inputted rotating quarter-wave plate then linear polarizer so that maximum power minimum of the outputted from can be detected, detected used ratio. (OSNR) using polarization-nulling method, comprises steps of: (a) linearly polarizing noise; (b) separating measure included bandwidth signal; (c) obtaining measured power.