Patent ID: 6160649
Filing Date: 2000-12-12
Classification: H04B

Abstract:
An optical power measuring system configured to send out selected one of a plurality of optical transmission signals having different wavelengths .lambda.1 through .lambda.n in a slightly intensity-modulated form with a measurement frequency fs onto an optically repeating transmission line and to measure optical power thereof in a particular repeater on the optical repeating transmission line, comprising:a tone signal generator for generating tone signals having a reference frequency fr and the measurement frequency fs which synchronize in phase;a reference signal light sender for sending reference signal light intensity-modulated by said reference frequency fr generated in said tone signal generator, the reference signal light having a wavelength .lambda.r different from the wavelengths .lambda.1 through .lambda.n of said optical transmission signals;a switching apparatus for selectively applying the tone signal of the measurement frequency fs generated by said tone signal generator to one of a plurality of optical transmission signal sender configured to output optical transmission signals with different wavelengths .lambda.1 through .lambda.n;a wavelength multiplexer for wavelength-multiplexing said optical transmission signals and the reference signal light output from said reference signal light sender and for outputting thus multiplexed signal onto said optical repeating transmission line;a divider in said particular repeater for dividing input light and for sending out one divisional optical output to a subsequent optical repeating transmission line;a measuring circuit in said particular repeater for reproducing a reference signal of said reference frequency fr and a to-be-measured signal having said measurement frequency fs and for measuring the optical power of said to-be-measured signal in accordance with a signal with a frequency corresponding to said measurement frequency fs obtained from said reference signal; anda signal transmitter in said particular repeater for transmitting a result of measurement by said measuring circuit to a predetermined station.