Abstract

Wavelength-division multiplexing (WDM) may enable highly functional and flexible optical networks in which wavelengths are used as routing paths [1]. The use of high-speed all-optical wavelength (λ) shifters may be critically required for dynamically reconfigurable networks and for networks requiring wavelength re-use due to an insufficient number of available wavelengths. One method of λ-shifting uses semiconductor optical amplifier (SOA) cross-gain compression [2] in which an intense optical pump signal modulates the SOA gain, inversely transferring the pump signal to a supplied weak CW probe. However, this method is incapable of shifting more than one input wavelength at a time, thereby severely limiting network functionality. We report here two different methods for all-optical wavelength shifting of multiple-input-wavelengths in a WDM routing node, (see Fig. 1). One technique involves spatial separation of incoming wavelengths and then shifting these multiple signals in parallel. Subcarrier-multiplexed routing control [3,4] and wavelength-interchange are incorporated to increase functionality. The second technique temporally interleaves the wavelengths and sequentially shifts the multiple signals. We measure error-free λ- shifting of 1-Gb/s data for all cases.

© 1996 Optical Society of America