摘要 |
The invention pertains to a method for determining and/or controlling the transmission wavelengths of transmission elements of an optical wavelength division multiplex transmission unit, in which the output signals of several optical transmission elements ( 7 ) with respectively one optical transmission spectrum ( 20 ) of different center wavelength (ë<SUB>sj</SUB>) are respectively fed to one optical input (E<SUB>2</SUB>, E<SUB>4</SUB>, . . . , E<SUB>n1</SUB>) of an optical wavelength monitoring and coupling unit ( 3 ) that combines the output signals into a wavelength division multiplex signal on one or more optical output(s) (A), with the wavelength monitoring and coupling unit ( 3 ) being designed such that an optical path, on which a narrow-band high-pass filtering or low-pass filtering takes place, exists between one, more or all inputs (E<SUB>2</SUB>, E<SUB>4</SUB>, . . . , E<SUB>n-1</SUB>), to which the output signal of a transmission element ( 7 ) is fed, and one or more additional inputs (E<SUB>1</SUB>, E<SUB>3</SUB>, . . . , E<SUB>n</SUB>) that are not connected to transmission elements ( 7 ). The filter characteristic on the path is chosen such that the entire spectral power of the signal filtered with the chosen characteristic changes during a shift in the center wavelength of the transmission spectrum ( 20 ) of a transmission element ( 7 ), the signal of which is fed into this path. The filtered optical signal appearing at one or more additional inputs (E<SUB>1</SUB>, E<SUB>3</SUB>, . . . , E<SUB>n</SUB>) is respectively fed to an optical reception element ( 9 ), the output signal of which is evaluated in order to determine the position and/or control the position of the transmission spectrum ( 20 ) of one or more of the optical transmission element(s) ( 7 ). Instead of providing a combined wavelength monitoring and coupling unit ( 3 ), it is also conceivable to utilize a separate wavelength monitoring unit ( 30 ) that may be designed analogous with respect to the filtering of the transmission signals. In this case, a fraction of the power of the output signals of the transmission elements is fed to the pertinent inputs. The combining of the individual output signals is realized with the aid of a separate coupling unit. The invention also pertains to a wavelength division multiplex transmission unit for implementing this method.
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