Passive Method for Raman Gain Measurement Using Backward Pumped Fiber Configuration

The passive measurement method for the Raman gain profile in singlemode fiber is presented in this work. Experimental technique is worked out for the standard fibers based on silica glass. The optical power density of amplified spontaneous emission for Stokes shifted region up to 1600 cm
^-1
was measured in the 50 km fiber span. The main advantage of the proposed method consists in the absence of external signals of variable frequency as it is used the measurement of amplified spontaneous emission in the idle mode of counter-pumped fiber Raman amplifier.