## 3 Experimental Results  
In order to demonstrate the power-equalization and wavelength switching capabilities of the proposed BMWC and evaluate the maximum supported bit rate and loud/soft ratio of the input packets, the BMWC was characterized at both 10 Gb/s and 20 Gb/s. The experimental results for 10 Gb/s operation are illustrated in Figure 2. The input traces of the incoming packets at \(\lambda_{1}\) = 1550.4 nm are shown in Figure 2a-c featuring two loud and three soft packets interleaved, while for comparison purposes Figure 2d-f depict that the respective output traces exhibit flat and equalized peak power levels for all bits, demonstrating both power-equalization and wavelength conversion, while the respective output eye diagrams are illustrated in Figure 2g-i.  
The 10 Gb/s operation of the BMWC was also evaluated with the aid of Bit Error Rate (BER) measurements for loud/soft ratios ranging from 4 dB up to 9 dB and the obtained BER curves are plotted in Figure 2j with the solid lines representing the output data signals and the dashed lines used  
Figure 1: Experimental setup for testing the proof of concept of the Burst-Mode Wavelength Converter (BMWC). EDFA: Erbium Doped Fiber Amplifier; ISO: Isolators; MZI: Mach Zehnder Interferometer; OBPF: Optical Bandpass Filter; PC: Polarization Controllers; PPG: Programmable Pattern Generators; PRBS: Pseudo Random Bit Sequences; SOA: Semiconductor Optical Amplifier; VOA: Variable Optical Attenuators.  
for the respective input data signals. As can be seen for the solid-line curves of the output signals, error free operation at \(10^{-9}\) was achieved for all loud/soft ratio values up to 9 dB. On the contrary, error free operation for the input signal was obtained only for loud/soft ratios up to 7 dB at the \(10^{-9}\) condition, up to 8 dB for the \(10^{-4}\) condition and could not be achieved for the 9 dB ratio. A better representation of this quantitative improvement of the BER curves between the input and output is shown in Figure 2k, where the required peak power for \(10^{-9}\) BER operation is plotted versus the loud/soft ratios, showing that error free operation could not be achieved for the input at high loud/soft power ratios. The latter reveals that the BER measurements were heavily degraded by the requirement for a low threshold value in the BER-tester to detect the pattern of the soft packets.  
Equivalently, the experimental results for 20 Gb/s operation are shown in Figure 3. The input traces of the incoming packets at \(\lambda_{1}=1550.4\) nm are shown in Figure 3a-c with two loud and three soft packets interleaved, while Figure 3d-f depict the respective flat and equalized peak power output traces of two consecutive packets at \(\lambda_{2}=1549.3\) nm. Figure 3g-i show the output eye diagrams with an extinction ratio (ER) of 6.2 dB and amplitude modulation (AM) of 1 dB, validating the credentials of the BMWC to operate at rates up to 20 Gb/s. Moreover, BER measurements were also performed for loud/soft ratios 3-5 dB, as plotted in Figure 3j, with solid lines used for the output signals and dashed lines for the input signals. The BER improvement between the input and output signals is depicted in Figure 3k showing up to 3.51 dB BER improvement for 5 dB loud/soft ratio when using the BMWC. The device characteristics (SOA lengths, saturation power levels, small signal gain etc.), as well as the operational conditions that allow SOA-MZI operating as BMWC are summarized in Table 1.  
Figure 2: Experimental results for 10 Gb/s for 4 dB loud/soft ratio (**a**) input trace (5 μs/div), (**d**) output trace (2 μs/div), (**g**) output eye diagram (50 ps/div). For 6 dB (**b**) input trace, (**e**) output trace, (**h**) output eye diagram. For 8 dB (**c**) input trace, (**f**) output trace, (**i**) output eye diagram, (**j**) Bit Error Rate (BER) measurements for input and output signals and (**k**) BER improvement of input–output signals at different loud/soft ratios. All traces and eyes are in 4 mV/div.