Simultaneous compensation for aberration and axial elongation in three-dimensional laser nanofabrication by a high numerical-aperture objective.
One of the challenges in laser direct writing with a high numerical-aperture objective is the severe axial focal elongation and the pronounced effect of the refractive-index mismatch aberration. We present the simultaneous compensation for the refractive-index mismatch aberration and the focal elongation in three-dimensional laser nanofabrication by a high numerical-aperture objective. By the use of circularly polarized beam illumination and a spatial light modulator, a complex and dynamic slit pupil aperture can be produced to engineer the focal spot. Such a beam shaping method can result in circularly symmetric fabrication along the lateral directions as well as the dynamic compensation for the refractive-index mismatch aberration even when the laser beam is focused into the material of a refractive index up to 2.35.
Centre for Micro-Photonics and CUDOS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Australia.
Benjamin P
BP
Cumming
Sukanta
S
Debbarma
Barry
B
Luther-Davis
Min
M
Gu