| 摘要 |
A WDM signal monitor (4) for measuring optical power and/or wavelength of components of a WDM signal is disclosed. The monitor comprises: a wavelength selectable light source (20), preferably wavelength tuneable laser, which is operable to produce an optical output at known selectable wavelengths; an optical receiver (24) to which said optical output and WDM signal are applied and which is operable to produce an electrical signal whose frequency is representative of the difference in wavelength between a component of the WDM signal and optical output; means (22) for determining the power of the component of the WDM signal from the magnitude of said electrical signal; and means (22) for determining the wavelength of the component form the wavelength selected and the frequency of said electrical signal. |
