➀ The commercial light source integration solutions are based on bonding technology, with advantages in high-precision alignment but high cleanliness requirements. ➁ On-chip direct growth on large silicon wafers offers potential low cost and CMOS compatibility, but challenges in epitaxy. ➂ A two-step growth technique is used to address fitting issues, with GaAs-on-V-groove Si (GoVs) as the mainstream template technique. ➃ A new bufferless solution with lateral growth is proposed, with advantages in defect limitation and easier coupling with silicon-based devices. ➄ Room-temperature lasing at 1500 nm波段 is achieved under optical pumping conditions, and the laser peak is related to the cavity length. ➅ PDs with excellent performance in terms of dark current, bandwidth, and responsivity are demonstrated.