In the past two decades, tremendous efforts have been exerted to understand and control the delivery of ultrashort laser pulses into various types of transparent materials ranging from glass and crystal to polymer and even bio-materials. This approach opens up the route toward determinative and highly localized modification within the transparent materials, enabling three-dimensional (3D) micromachining of the materials into sophisticated structures and devices with the extreme geometrical flexibility, which further promotes a broad spectrum of scientific, technological, and industrial applications. Despite the tremendous progress made on fabricating various sophisticated components by ultrashort laser micromachining, it remains extremely hard to scale the laser fabrication to macro-scale object with large height, due to the incapability of traditional techniques failing in achieving concentration of laser energy deeply inside the transparent materials under processing.

 

In this work, we clearly identified a new laser-material interaction regime through delicate pump-probe microscopy utilizing ultrashort laser pulses. The observed ultrafast spatiotemporal dynamics of fused silica glass excited by loosely focused laser pulses with femtosecond and picosecond durations, reveal an exceptional incubation effect originating from self-regulated multiple-pulse interactions with accumulated material changes in the picosecond regime, which enables highly localized concentration of the laser energy well beyond the diffraction limit of light. The unfolded laser-material interactions enable rapid three-dimensional (3D) glass-printing of macro-scale object with geometrical complexity at robust micro-scale resolutions. In particular, a 4 cm-height sculpture reproducing the exquisite Chinese treasure Four-sheep statue is successfully fabricated in fused silica glass. The discovered ultrashort laser-material interaction challenges the orthodox beliefs of the focal volume dependent material modifications, providing renewed and vigorous impetus to the long-standing study of materials exposed to high-power pulsed radiations. At the same time, the established 3D glass-printing technique hold fascinating perspectives in high-throughput massive manufacturing of numerous devices of significant scientific and technical importance, including microfluidic-chips, biomimetic components, and large-scale integrated optoelectromechanics.