In this paper, the on-chip beam splitting methods in recent years are reviewed, the research progress, optimization design methods, implementation functions and applications of several main beam splitting methods are introduced, and the applications of on-chip beam. In this paper, the on-chip beam splitting methods in recent years are reviewed, the research progress, optimization design methods, implementation functions and applications of several main beam splitting methods are introduced, and the applications of on-chip beam. In this paper, we describe a 2-stage laser beam-splitting strategy based on both polarization re-fractive and diffractive optics, and its implementation into independent modules. In the first stage, only refractive polarization optics is used and a variable number of sub-beams is produced, each. This white paper provides an in-depth look at beam splitters, essential hardware for quantum technologies, with applications in quantum computing and quantum key distribution. Beam splitters facilitate quantum information processing and secure communication protocols, playing an important role in. This paper reviews the on-chip beam splitting methods in recent years, which are mainly divided into the following categories: y-branch, multimode interference coupling, directional coupling, and inverse design. We consider triangular cross-section single-mode waveguides for the design of a directional coupler. We optimize parameters for a 50:50. uires eficient single photon generation, manipulation, entanglement, and detection [10–12]. Beamsplitters (BS) play a crucial role in on-chip photonic QIP circuits for generating multiphoton correlation [8,13] and can be used to realize several important operations like enta glement generation and. We report on the fabrication of waveguides and beam splitters in pure YAG crystals by femtosecond laser direct writing (FLDW).