Simultaneous all-optical wavelength conversion of baseband payload and removal/replacement of subcar - Optical Fiber Communications, 1996. OFC '96

input pump, which is much smaller than individual SOA polarization dependence. Secondly, the worst contrast ratio still yields -6.5 dB for an input contrast ratio 10 dB, which is still larger than the contrast ratio of the TE input for a single SOA. The residual 1.1-dB polarization dependence is attributed to the two SOAs not being perfect matched. Figure 3(a) shows the polarization dependence of the BER measurement. A polarization dependence of power penalty of 3 dB and 4 dB is measured for SOA, and SOA, respectively As expected, the degradation of contrast ratio for TM mode pump incurs big power penalty (-5 dB), which will severely limit the system performance. Figure 3(b) shows the polarization dependence of our proposed module (SOA' I SOA2). The polarization dependence decreases to merely 0.5 dB and the largest power penalty is only 1.5 dB. This significant improvement is due to the reduced polarization fluctuation of contrast ratio over much enhanced contrast ratio. Finally, the proper polarization alignment is critical to achieve this improvement. In the case of (SOAII(SOA,), the polarization dependence increases to 2.5 dB and the largest penalty increases to 3 dB. 1. J. M. Wiesenfeld, J. S. Perino, A. H. Gnauck, and B. Glance, "Bit-error-rate Performance for Wavelength Conversion at 20 Gb/s," Electron. Lett. 30, 720-721 (1994). 2. B. Mikkelsen, T. Durhuus, R. J. Pedersen, K. E. Stubkjaer, M. Oberg, and S. Nilsson, "Penalty Free Wavelength Conversion of 2.5 Gbit/s Signals Using a Tunable DBR-laser," in Proc. European Conference on Optical Communications '92, September 1992, Berlin, Germany, paper WeA10.4. 3. G. Grosskopf, R. Ludwig, and H. G. Weber, "140 Mbit/s DPSK Transmission Using an All-Optical Frequency Convertor With a 4000 GHz Convertor Range," Electron. Lett.