Research

Achieving super-resolution imaging and processing has been a longstanding goal in the field of optics. In 1994, German scientist Stefan Hell proposed the stimulated emission depletion (STED) mechanism, achieving sub-10 nm super-resolution imaging and earning the Nobel Prize in 2014. However, this mechanism is not applicable to typical solids. Additionally, due to the intense interaction between light and matter, the difficulty of achieving super-resolution processing far surpasses that of super-resolution imaging. As a result, three-dimensional super-resolution processing of solid materials has remained an unsolved challenge in the field of optics. Addressing these issues, Prof. Hong-Bo Sun for the first time internationally discovered the Optical Far-field Induced near-field Breakdown (O-FIB) effect. This effect utilizes nanoscale damage induced by laser irradiation on materials as seeds for the optical near fields, allowing the laser focus to "carry" optical near-field itself freely through three-dimensional space. This breakthrough shattered the two-dimensional constraints, enabling the three-dimensional "propagation" of optical near fields. As a result, it achieved three-dimensional super-resolution processing with a precision of up to 7 nanometers for transparent solids, marking a significant breakthrough in the field of nano-optics (Light Sci Appl, 9,41,2020). Prof. Hong-Bo Sun further proposed the Threshold Tracking and Lock-In (TTL) technique, successfully achieving sub-5nm precision laser manufacturing in experiments. Under these conditions, the breakdown area defined by the gradient of laser energy fails, and atomic erosion is predominantly governed by fluctuations in the position of primary electrons and energy. This manifests as random atomic breakdown or removal within a small area (only a few nanometers, specific values dependent on the material, Light Sci Appl, 13,6,2024). Consequently, the precision of laser manufacturing has reached the quantum limit, marking a new milestone following the optical diffraction limit.