Fig. 1. Device epitaxial layer structure and microscope images. (a) Schematic of the device epitaxial structure; (b) microscope image of the waveguide and MMI; microscope images of (c) 1×2, (d) 1×3, and (e) 1×4 photodetector arrays

Fig. 2. Device test results. Frequency responses of (a) 1×2, (b) 1×3, and (c) 1×4 photodiode arrays; (d) RF output powers of a 1×4 photodiode array at different frequencies

Fig. 3. Intensity modulation direct detection experiment. (a) Schematic of experimental setup; eye diagrams and bit error rates of the received (b) 60 Gbaud and (c) 100 Gbaud PAM4 signals