Apparatus for measuring wavelength and optical power and optical signal-to-noise ratio of an optical signal in wavelength-division multiplexing optical communications

摘要

PURPOSE: An apparatus for measuring a wavelength of an optical signal, an optical strength and an optical signal-to-noise ratio in a wavelength division multiplexing optical communication is provided to heighten an accuracy in measuring an optical strength and optical signal-to-noise ratio by measuring them by using a signal-band reflection optical filter. CONSTITUTION: An optical amplifier(502) receives a wavelength division-multiplexed optical signal, amplifies it and outputs it together with a spontaneous emission light. As a band pass optical variable filter(506), a Fabry-Perot variable filter, an integrated optical device containing grid, a multi-layer thin film device, or an acousto-optic filter may be adopted. An optical circulator(508) includes three input/output terminals, of which input and output correspond clockwise. That is, when a light is inputted to an arbitrary terminal, it is output to the next terminal clockwise. An optical fiber Bragg grids(510,512) reflect a light corresponding to a grid period and pass a light of the remaining wavelength. In addition, the optical fiber Bragg grids(510,512) reflect only a particular wavelength component of the spontaneous emission light and outputs a spontaneous emission light discrimination signal.