Abstract: In Raman gain slope measurement method and device measures Raman gain slope which is a value obtained by normalizing a gain generated by Raman amplification caused by pump light incident on an optical fiber by optical power of the pump light in question. The method and device measures the power of noise light and operates based on a relationship between the optical power of pump light incident on an optical fiber and the optical power of the measured noise light generated by the application of the pump light, Raman gain slope of the optical fiber in question is thus calculated.

Abstract: A Raman amplifier of the present invention includes a loss measuring unit (110) for measuring loss distribution of an object of measurement by OTDR based on reflected light with respect to outputted test light; an optical coupler (114) in which the test light is supplied to a first input terminal thereof and one of output terminals thereof is connected to an optical fiber transmission line; a wavelength filter (116) inserted between the loss measuring unit (110) and the optical coupler (114); a control circuit (200) for generating a control signal for reducing an error signal obtained by comparing a Raman gain obtained with a reference value; and an excitation light source (140) for changing an excitation light power based on the control signal.

Abstract: A Raman gain control method of controlling a Raman gain caused by simultaneous application of pump lights of a plurality of wavelengths to an optical fiber, which includes, based on a relation of a ratio coefficient which is a ratio of power of each pump light to total power of all the pump lights with the Raman gain, from a designated value of the Raman gain, calculating power of each pump light realizing the designated Raman gain within a designated wavelength range, and controlling power of each pump light applied to the optical fiber to apply each pump light at each power calculated.

Abstract: A Raman amplifier of the present invention includes a loss measuring unit (110) for measuring loss distribution of an object of measurement by OTDR based on reflected light with respect to outputted test light; an optical coupler (114) in which the test light is supplied to a first input terminal thereof and one of output terminals thereof is connected to an optical fiber transmission line; a wavelength filter (116) inserted between the loss measuring unit (110) and the optical coupler (114); a control circuit (200) for generating a control signal for reducing an error signal obtained by comparing a Raman gain obtained with a reference value; and an excitation light source (140) for changing an excitation light power based on the control signal.

Abstract: A Raman amplifier of the present invention includes a loss measuring unit (110) for measuring loss distribution of an object of measurement by means of OTDR based on reflected light with respect to outputted test light; an optical coupler (114) in which the test light is supplied to a first input terminal thereof and one of output terminals thereof is connected to an optical fiber transmission line; a wavelength filter (116) inserted between the loss measuring unit (110) and the optical coupler (114); a control circuit (200) for generating a control signal for reducing an error signal obtained by comparing a Raman gain obtained with a reference value; and an excitation light source (140) for changing an excitation light power based on the control signal.

Abstract: A Raman gain control method of controlling a Raman gain caused by simultaneous application of pump lights of a plurality of wavelengths to an optical fiber, which includes, based on a relation of a ratio coefficient which is a ratio of power of each pump light to total power of all the pump lights with the Raman gain, from a designated value of the Raman gain, calculating power of each pump light realizing the designated Raman gain within a designated wavelength range, and controlling power of each pump light applied to the optical fiber to apply each pump light at each power calculated.

Abstract: In Raman gain slope measurement for measuring Raman gain slope which is a value obtained by normalizing a gain generated by Raman amplification caused by pump light incident on an optical fiber by optical power of the pump light in question, based on a relationship between optical power of pump light incident on an optical fiber and optical power of noise light generated by the application of the pump light, Raman gain slope of the optical fiber in question is calculated.

Abstract: A Raman amplifier of the present invention includes a loss measuring unit (110) for measuring loss distribution of an object of measurement by means of OTDR based on reflected light with respect to outputted test light; an optical coupler (114) in which the test light is supplied to a first input terminal thereof and one of output terminals thereof is connected to an optical fiber transmission line; a wavelength filter (116) inserted between the loss measuring unit (110) and the optical coupler (114); a control circuit (200) for generating a control signal for reducing an error signal obtained by comparing a Raman gain obtained with a reference value; and an excitation light source (140) for changing an excitation light power based on the control signal.