Continuous-Wave Band Translation between the Near-Infrared and Visible Spectral Ranges

Wavelength conversion based on degenerate four-wave mixing in a photonic crystal fiber with two zero-dispersion wavelengths is investigated both theoretically and experimentally. The proposed concept of universal band translation in a single- pass traveling-wave structure offers wavelength-band rather than isolated-wavelength mapping between distant spectral ranges. Near-infrared signals are modulated using both harmonic and pseudo-random bit sequences, and translated to the visible band suitable for submarine communications. The translated idlers are tuned within the visible band by continuous pump- or signal-wavelength tuning. Multiple-channel translation which produces wavelength- division-multiplexed idlers in the visible band is demonstrated for the first time. The performance of the translation process is measured both spectrally and temporally, for both single- and multiple- channel signals.