The invention relates to an adjustable ring-shaped vector beam generating
system. The prior art has high
incident beam requirements, and cannot realize the ring-shaped vector beam and the
beam size adjustment. In the invention, the
incident beam sequentially passes through a beam expanding shaper, an external reflection circular
conical surface reflector, a cylindrical curved
polarizer, an internal reflection circular
conical surface reflector, and two halfwave plates positioned in parallel; after a
light source emergent beam passes through the beam expanding shaper and the external reflection circular
conical surface reflector, a radial propagating beam is formed; a ring-shaped rotation vector polarized beam is formed by the reflection of the internal reflection circular conical surface reflector after the radial propagating beam passes through the cylindrical curved
polarizer; the polarization state is changed by adjusting the
optical axis angle of the two halfwave plates through a rotary motion part; and the transverse size of the beam is changed by adjusting the space between the external reflection circular conical surface reflector and the internal reflection circular conical surface reflector through an axial motion part. The invention has the advantages of low
incident beam requirements, ring-shaped vector beam output, convenient
beam polarization state and transverse
size adjustment, etc.