摘要
A fiber-based,self-aligned dual-beam laser direct writing system with a polarization-engineered depletion beam is designed,constructed,and tested.This system employs a vortex fiber to generate a donut-shaped,cylindrically polarized depletion beam while simultaneously allowing the fundamental mode excitation beam to pass through.This results in a co-axially self-aligned dual-beam source,enhancing stability and mitigating assembly complexities.The size of the central dark spot of the focused cylindrical vector depletion beam can be easily adjusted using a simple polarization rotation device.With a depletion wavelength of 532 nm and an excitation wavelength of800 nm,the dual-beam laser direct writing system has demonstrated a single linewidth of 63 nm and a minimum line spacing of 173 nm.Further optimization of this system may pave the way for practical superresolution photolithography that surpasses the diffraction limit.
基金
National Natural Science Foundation of China(12274299,92050202)
Science and Technology Commission of Shanghai Municipality(22QA1406600)
Natural Science Foundation of Shanghai Municipality(20ZR1437600).
