Energy-efficient all optical wavelength converter for optical phase conjugation

Abstract

Abstract All-optical wavelength converters (AOWCs) based on state-of-the-art highly nonlinear optical fibers (HNLFs) are best matched with future large-capacity optical networks because of their characteristic of fast response. AOWCs play important roles in wavelength-routed optical networks to alleviate the constraint of conflicted wavelengths and in optical phase conjugation networks to mitigate the effects of fiber nonlinearities. Generally, conversion efficiency (CE) is a key evaluation index of AOWCs and higher CE corresponds to better transmission performance. However, it is challenging to achieve higher CE because the launched pump powers into HNLFs are usually limited by their stimulated Brillouin scattering thresholds. Actually, the performance of AOWCs, i.e., that of the idlers, depends on both of their CEs and the signal powers. Thus, it is feasible to achieve good performance for AOWCs with lower CEs as that with higher CEs by optimizing the launched signal powers into HNLFs. Our experimental results verified the above proposal in the AOWCs with the CEs of –23.1 dB, −19.1 dB, −15.2 dB, −11.4 dB and −7.9 dB. The proposed AOWCs was used as optical phase conjugation in the 64-QAM coherent optical transmission experimental system and good compensation performances have been achieved under the above five operating conditions.