Creation of multifocal arrays and their application in nanofabrication

This book presents theoretical and experimental investigations into optical properties of tightly focused vectorial optical beams with high numerical-aperture objectives and their applications in laser nanofabrication. Based on the vectorial Debye diffraction theory, the focusing properties of optical beams are firstly studied by manipulating light polarisation, amplitude and phase. Afterwards, the experimental generation of the corresponding focused beams is demonstrated with a spatial light modulator (SLM). Such laser beams can be applied in direct laser writing (DLW) technique to fabricate arbitrary micro/nanoscaled three-dimensional (3D) structures in optical sensitive materials. As two major challenges in DLW nanofabrication, the axial elongation of the focal spot and the low processing speed are solved by employing the amplitude- and phase-modulated beam engineering methods in conjunction with an SLM. Hence, a new technique named dynamic laser printing, which is able to produce a 3D photonic device at a time by using a high-quality multifocal array, is developed to boost the fabrication speed by two orders of magnitude compared with the traditional DLW method.