Is Monstar topologically the same as lemon?

Abstract

Topological structure of monstar in -symmetric fields with index Ic= +1/2 and three radial lines ending at C-point is an intermediate structure having properties of lemon and star. We experimentally realized monstar pattern in polarization ellipse orientation via three different routes, from lemon pattern using topologically-invariant squeezing and / or rotation transformations. Our results suggest that lemon and monstar can smoothly transform into each other under any or combination of these transformations leading to one interpretation that monstar is an anisotropic lemon.