The invention discloses a
polarization beam splitter based on a
silicon dioxide optical
waveguide, and belongs to the technical field of
photon integration. The
optical fiber sequentially consists of a substrate, a lower cladding, a core layer
waveguide and an upper cladding, wherein the core layer
waveguide is coated by the upper cladding; the lower cladding layer and the upper cladding layer are made of
silicon dioxide, the core layer waveguides have the same height, are made of
germanium-doped
silicon dioxide, and are composed of a first 1 * 1 MZI waveguide Core1, a middle straight waveguide Core2 and a second 1 * 1 MZI waveguide Core3; when the waveguide spacing in the middle area of the core layer waveguide is close enough, the core layer waveguide can be regarded as a
grating-like structure, so that the average effective refractive indexes of a TE mode and a TM mode in the area are different,
coupling and multi-mode interference of light
modes are generated at the same time, and after a certain length, the TE mode and the TM mode generate a
phase difference, so that the interference of the TE mode and the TM mode is reduced. And finally, carrying out polarization separation and respectively outputting from two ports. The polarization
multiplexing technology of a low-refractive-index-difference platform is achieved, or unwanted polarization states are filtered out in a polarization-sensitive device.