Compared with the optical system composed of traditional optical devices, the photonic integrated circuit composed of on-chip optical devices has the advantages of wide bandwidth, easy implementation of dense wavelength division multiplexing (WDM), compact structure, light. Compared with the optical system composed of traditional optical devices, the photonic integrated circuit composed of on-chip optical devices has the advantages of wide bandwidth, easy implementation of dense wavelength division multiplexing (WDM), compact structure, light. As a basic and important link in on-chip photon propagation, beam splitting is of great significance for the efficient utilization of sources and the compact integration of optoelectronic devices. It is widely used in power splitting, polarization separation, wavelength division multiplexing and. A beam splitter or beamsplitter is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications. It operates based on the principles of reflection and refraction. Common beamsplitters include T30/R70, T50/R50/ and T70/R30, and some manufacturers provide customized services. They can customize the beam splitter to.