Fig 1.
Spine-leaf data center architecture utilizing fiber-based links.
Fig 2.
Optical PAM-4 signal synthesis from two binary inputs using an EAM.
Fig 3.
Demodulation of Channel-1 data by employing the transfer function of an EAM.
Fig 4.
Demodulation of Channel-2 data by employing the transfer function of an MZM.
Fig 5.
Simulation setup of our proposed PAM-4 based data center architecture.
Fig 6.
Two optical comb signals obtained at the output of the DD-MZM, centerd at 225.41 THz and 228 THz, respectively.
Fig 7.
Eye diagrams for channel-1 for OSNR of 20 dB when transmitted (a) over fiber using a laser source of 225.41 THz, (b) over FSO using a laser source of 225.41 THz, (c) over fiber using laser source 228 THz and (d) over FSO using laser source 228 THz.
Fig 8.
Eye diagrams for channel-2 for OSNR of 25 dB when transmitted (a) over fiber using a laser source of 225.41 THz, (b) over FSO using a laser source of 225.41 THz, (c) over fiber using laser source 228 THz and (d) over FSO using laser source 228 THz.
Fig 9.
OSNR versus BER performance of the PAM-4 signal for (a) Channel-1 and (b) Channel-2.
The results have been obtained for the two different optical sources and optical paths.
Table 1.
Comparison of the proposed PAM-4 modulation scheme with existing techniques.