Polarization-maintaining optical isolator based on optical rotation fiber

The invention discloses a polarization-maintaining optical isolator based on an optical rotation optical fiber, and relates to the field of optical passive devices, the polarization-maintaining optical isolator comprises a first single-polarization optical fiber at an inlet end, a second single-polarization optical fiber at an outlet end and the optical rotation optical fiber, the optical rotation optical fiber is welded between the first single-polarization optical fiber and the second single-polarization optical fiber, and a magnetic field in the same direction as the optical rotation optical fiber is matched in the middle of the optical rotation optical fiber. The magnetic field intensity is matched with the length of the optical fiber, and the magnetic field enables light to clockwise rotate by 45 degrees in the optical rotation optical fiber. The optical rotation optical fiber in a magnetic field can clockwise rotate light by 45 degrees, and is matched with the characteristics that light energy in the sl