Research

Nanoscale fabrication techniques represented by photolithography, nanoimprinting, electron beam lithography, and focused ion beam fabrication have found crucial applications at the forefront of industry and science. The electronic chips forming the hardware foundation of the information society are realized through semiconductor lithography methods, showcasing precision down to several nanometers. However, these techniques are inadequate for fabricating complex three-dimensional geometries and are unsuitable for hard, brittle specialty materials beyond semiconductors.

Addressing these limitations, Prof. Sun first reported in 1999 the use of photo-polymerizable resin materials induced by femtosecond laser-induced two-photon polymerization to fabricate three-dimensional photonic devices - photonic crystals (Appl. Phys. Lett.74,786,1999, SCI citation: 554 times). He subsequently proposed the use of threshold effects to achieve multi-photon laser micro/nano fabrication beyond the diffraction limit, creating three-dimensional sculpted "nano bulls" (Nature, 412, 697, 2001, SCI citation: 2453 times), demonstrating a fabrication resolution of 120 nanometers. This work marked the emergence of an intrinsic three-dimensional machining capability in nanotechnology, garnering widespread attention from academia and the public, leading to extensive coverage by over a hundred internationally renowned media outlets such as CNN, BBC, among others.

As a result, Prof. Hong-Bo Sun received commendation from the Minister of Education, Culture, Sports, Science, and Technology of Japan. The Japanese government allocated 100 million yen to establish the Sun Laboratory for femtosecond laser micro/nano processing at Osaka University. Over the past two decades, Professor Sun's pioneering contributions to the field of femtosecond laser micro/nano processing have received broad recognition, with his papers cited over 30,000 times in SCI - a remarkable feat in the laser manufacturing domain, serving as a testament to his achievements.