Polarization-independent optical spectral inversion without frequency shift using a single semiconductor optical amplifier

Two schemes for polarization-independent spectral inversion without frequency shift have been experimentally demonstrated. Both schemes use two pump beams and a polarization-insensitive semiconductor amplifier. Polarization-independent optical spectral inversion without frequency shift was obtained for lower wavelength detuning between the two pump beams in the first scheme and for large wavelength detuning in the second scheme. Combining these two schemes allows polarization-independent spectral inversion without frequency shift to be obtained over a quite wide frequency range. The results are in good qualitative agreement with theoretical predictions.