Active optical pulse compression with a gain of 29.0 dB by using four-wave mixing in an optical fiber

The four-wave mixing gain in an optical fiber strongly depends on the nonlinear phase mismatch when the pump power itself causes a nonlinear index change. The peak of the pump pulse has a much higher gain than its wings, and so this process can be used to obtain efficient pulse compression. A 93-ps signal pulse at 1569.9 nm is compressed to as short as 20 ps with a gain of 29.0 dB. The wavelength-converted signal at 1559.9 nm is simultaneously compressed to 21 ps and amplified by 28.9 dB as compared with the original signal.