Fig. 1. (a)Schematic diagram of HOBGs MOPA semiconductor laser, (b) epitaxial layer structure of HOBGs MOPA semiconductor laser

Fig. 2. Reflection spectrum of HOBGs MOPA laser at different etch depths

Fig. 3. Transmission spectrum of HOBGs MOPA laser at different etch depths

Fig. 4. Loss spectrum of HOBGs MOPA laser at different etch depths

Fig. 5. Light power-current-voltage curve graph of HOBGs MOPA laser

Fig. 6. Optical spectrum of HOBGs MOPA device at 2.5 A

Fig. 7. The lateral far field patterns of HOBGs-MOPA laser. The far-field spot is shown in the figure.