The AIM PDK-based receiver, shown in Figure 2(c), is contained in the CC aimRX, and contains a Si edge coupler, waveguide, and Ge photodetector.
For the complete design, the initial 0 dBm cw source incurs a total optical loss of approximately -17 dB as can be seen in the signal summaries at various ports after the simulation. The transmitter PIC loss is approximately -14.3 dB, while the receiver PIC loss is approximately -2.7 dB. The average loss of the MZM, taking into account both insertion loss and modulation, is approximately 8.8 dB.
Figure 3 depicts the eye diagram at the photodetector output, whose average current is approximately 17.2 µA. The extinction ratio of the received eye diagram is approximately 6 dB. The bitrate can be increased to 20 Gb/s without inducing any degradation in extinction ratio. At a bitrate of 25 Gb/s, the extinction ratio is expected to be around 5 dB which can be increased by driving with 1.2 Vpp electrical signals.