Sidelobe reduction of tightly focused radially higher-order Laguerre-Gaussian beams using annular ma
Sidelobe reduction of tightly focused radially higher-order Laguerre-Gaussian beams using annular masks.
We report the reduction of sidelobes in tight focusing patterns of radially higher-order Laguerre-Gaussian (LG) beams with nonhelical phase structures. Numerical calculations based on the vectorial Debye theory reveal that a class of annular masks reduces sidelobes in the tight focusing patterns only for radially even-order LG beams. The present scheme produces small focal spots beyond the diffraction limit suitable for application to scanning microscopy, laser fine processing, etc.
Ohtake Y, Ando T, Inoue T, Matsumoto N, Toyoda H.