Fig. 1. (a) Schematic diagram of the thermal tuning structure. (b) Simulated temperature distribution when the heater power is 4.63 mW. (c)–(h) Simulated temperature distribution of waveguide when the heater power is (c) 1.37 mW, (d) 4.63 mW, (e) 6.47 mW, (f) 8.33 mW, (g) 10.1 mW, and (h) 11.73 mW.

Fig. 2. (a) Absorption coefficient lines of Ge0.992Si0.008 at ON and OFF states. (b) FOM variation with wavelength at different temperatures.

Fig. 3. Schematic diagram of (a) device structure, (b) cross section, and (c) SEM image.

Fig. 4. Electro-optical setup diagram. (a) DC link, (b) bandwidth link, and (c) eye diagram link.

Fig. 5. Measured (a) transmission loss, (b) extinction ratios, and (c) fitting FOM of the EAM under different bias voltages.

Fig. 6. Measured (a) insertion loss and (b) extinction ratio at different heater power. (c) Fitting FOM at different heater power.

Fig. 7. (a) Measured transmission loss at 3 V reverse bias. (b) Wavelength changes with the heater power under 15 dB transmission loss at 3 V reverse bias.

Fig. 8. (a) Effect of light current and dark current as a function of DC bias. (b) 3 dB EO bandwidth of the device under different DC biases.

Fig. 9. 80 Gbit/s NRZ eye diagrams of the EAM at different heater power: (a) 0 mW, (b) 1.37 mW, (c) 4.63 mW, (d) 6.47 mW, (e) 8.33 mW, and (f) 10.1 mW.

Fig. 10. (a) 80 Gbit/s NRZ electric eye diagram. (b)–(l) 80 Gbit/s NRZ eye diagrams of the EAM at different heater power: (b) 0 mW, (c) 0 mW, (d) 0 mW, (e) 1.37 mW, (f) 1.37 mW, (g) 4.63 mW, (h) 4.63 mW, (i) 6.47 mW, (j) 6.47 mW, (k) 8.33 mW, and (l) 10.1 mW.

Fig. 11. 100 Gbit/s PAM4 eye diagrams of the EAM at different heater power: (a) 0 mW, (b) 1.37 mW, (c) 4.63 mW, (d) 6.47 mW, (e) 8.33 mW, and (f) 10.1 mW.

Fig. 12. 100 Gbit/s PAM4 eye diagrams of the EAM at different heater power: (a) 0 mW, (b) 0 mW, (c) 0 mW, (d) 1.37 mW, (e) 1.37 mW, (f) 4.63 mW, (g) 4.63 mW, (h) 6.47 mW, (i) 6.47 mW, (j) 8.33 mW, and (k) 10.1 mW.

Fig. 13. 100 Gbit/s NRZ eye diagrams of the EAM at heater power (a) 0 mW and (b) 8.5 mW. 200 Gbit/s PAM4 eye diagrams of the EAM at heater power (c) 0 mW and (d) 8.5 mW.