Experimental Study of All-Optical Gain-Clamped Fiber Optical Parametric Amplifier

We report an experimental investigation of all-optical gain clamping in a fiber optical parametric amplifier. Signal gain variation was reduced to less than 0.5 dB when the signal input power varied from -25 to -5 dBm. Gain saturation effects were reduced, and we also observed reduction of cross-gain modulation to below 0.5 dB. Power penalties for a 3-Gb/s on-off keying signal were reduced from 2.5 to 0.5 dB.