Sharp focusing of a mixture of radially and linearly polarized beams using a binary microlens

Using a binary microlens of diameter 14 µm and focal length 532 nm (numerical aperture NA = 0.997), we focus a 633-nm laser beam composed of a mixture of radially and linearly polarized waves obtained by reflection of a linearly polarized Gaussian beam from a gold-coated subwave-length binary four-zone diffractive optical microelement (micropolarizer) of size 100×100 µm to a near-surface, near-circular focal spot of size (0.37±0.02)λ and (0.39±0.02)λ, where λ is wave-length. A linearly polarized light beam forms an elliptical focal spot with diameters (0.35±0.02)λ and (0.41±0.02)λ. Both focal spots have the area of 0.133λ². Subwavelength focusing using two microoptical components (a binary microlens and a micropolarizer) is suggested for the first time.