Large Second Harmonic Generation of Inp/SiO₂ Multilayer in Temperature Range of 80–673 K

III‐V compound semiconductors, represented by indium phosphide (InP), demonstrate great potential in the field of nonlinear optics (NLO) due to their high nonlinear susceptibility. However, achieving high second harmonic generation (SHG) efficiency and good atmospheric stability remains a critical challenge for InP‐based NLO devices, limiting their practical applications. In this work, the vapor‐liquid‐solid (VLS) growth of InP/SiO 2 multilayer is reported, which does not require strict epitaxially‐grown conditions. SHG results show that the InP/SiO 2 multilayer demonstrates a remarkably enhanced intensity 12 times higher than that of the InP wafer, yielding an equivalent second‐order nonlinear susceptibility up to 7.15 × 10 −10 m V −1 . Transfer matrix method (TMM) simulations show that the large SHG response can be attributed to the amplified local electric fields and enhanced light‐matter interactions within the InP/SiO 2 multilayer. In addition, the hybrid film exhibits excellent SHG emission stability without degeneration over a wide temperature range of 80–673 K in air conditioning. The large SHG activity of InP/SiO 2 multilayer paves the way for the development of high‐performance NLO devices.