Fig. 1. Schematic diagram of device structure

Fig. 2. Diagram of MMI light field distribution

Fig. 3. Diagram of relationship between changes in W_mid and W_bot and L_Δ or insertion loss. (a) Diagram of relationship between W_mid and W_bot changes and L_Δ; (b) diagram of relationship between W_mid and W_bot changes and insertion loss

Fig. 4. Diagram of relationship between manufacturing error and insertion loss change

Fig. 5. Diagram of comparison of PIV curves of devices

Fig. 6. Diagram of light spot distribution of devices with different currents. (a) MMI-LD, I=0.06 A; (b) MMI-LD, I=0.50 A; (c) MMI-LD, I=1.00 A; (d) DTM-LD, I=0.06 A; (e) DTM-LD, I=0.50 A; (f) DTM-LD, I=1.00 A

Fig. 7. Diagram of comparison of device temperature drift characteristics. (a) MMI-LD; (b) DTM-LD

Fig. 8. Diagram of comparison of device manufacturing error and output power