Fig. 1. (a) Schematic diagram of the finite element simulation structure; (b) relative figure of merit for transverse modes when inserting different InP thicknesses in active region

Fig. 2. Thermal simulation results of (a) single active region device and (b) double active region device

Fig. 3. (a) X-ray double diffraction and their (b) enlarged images of Sample 1 and Sample 2

Fig. 4. Schematic diagram of (a) Device 1 and (c) Device 2; cross-sectional SEM images of the front cavity of (b) Device 1 and (d) Device 2

Fig. 5. (a) PIV curves of Device 1 and Device 2 in continuous wave; (b) spectra of Device 1 and Device 2 at threshold current

Fig. 6. Far fields of Device 1 and Device 2 in the (a) slow axis direction and (b) fast axis directions