We propose a novel technique for high-density, all-optical magnetic recording based on vector diffraction theory. Our results demonstrate that a doughnut-shaped Gaussian beam with circular polarization (CPDGB), when tightly focused through a high numerical aperture (NA) lens, can generate nanoscale magnetization domains via the Inverse Faraday Effect. For NA = 0.85, the focused beam produces a magnetization spot with a subwavelength full width at half maximum (FWHM) of 0.4λ and a focal depth of 9λ. By incorporating a specially designed Multi-Belt Complex Phase Filter (MBCPF), the focal depth is significantly extended to 49λ while maintaining a subwavelength FWHM of 0.39λ. This highly elongated and precisely confined magnetic probe holds strong potential for applications such as all-optical magnetic recording (AOMR), compact opto-magnetic devices, magnetic particle manipulation, magnetic lattices for spin-wave operations, and advanced imaging methods like confocal and magnetic resonance microscopy.
