Progress in ultrafast laser processing and future prospects

Abstract

Abstract:The unique characteristics of ultrafast lasers have rapidly revolutionized materials processing after their first demonstration in 1987. The ultrashort pulse width of the laser suppresses heat diffusion to the surroundings of the processed region, which minimizes the formation of a heat-affected zone and thereby enables ultrahigh precision micro-and nanofabrication of various materials. In addition, the extremely high peak intensity can induce nonlinear multiphoton absorption, which extends the diversity of materials that can be processed to transparent materials such as glass. Nonlinear multiphoton absorption enables three-dimensional (3D) micro-and nanofabrication by irradiation with tightly focused femtosecond laser pulses inside transparent materials. Thus, ultrafast lasers are currently widely used for both fundamental research and practical applications. This review presents progress in ultrafast laser processing, including micromachining, surface micro-and nanostructuring, nanoablation, and 3D and volume processing. Advanced technologies that promise to enhance the performance of ultrafast laser processing, such as hybrid additive and subtractive processing, and shaped beam processing are discussed. Commercial and industrial applications of ultrafast laser processing are also introduced. Finally, future prospects of the technology are given with a summary.

Terahertz Radiation Modulated by Confinement of Picosecond Current Based on Patterned Ferromagnetic Heterostructures

“…A mode-locked Ti:sapphire laser (120 fs pulse duration, 1 kHz repetition rate) operating at a wavelength of 800 nm is used for the femtosecond laser direct writing. [26] As shown in Figure 1b, the laser beam in Gaussian mode is focused via 50Â microscope objective (numerical aperture is 0.55, Nikon ECLIPSE 80i) onto the sample at a scan speed of 100 μm s À1 , which are placed on the XYZ piezo-translation stage. The planar-patterned heterostructures are created by focusing laser pulses on the surface with the beam spot around 2 μm.…”

Advances and opportunities of ultrafast laser synthesis and processing

“…This distinct feature offers three different schemes in 3D micro-and nanoprocessing, subtractive, undeformative, and additive processing. 27 As described in the article by Jiang et al in this issue, several products are available that take advantage of ultrafast laser 3D densifi cation that occurs in glasses that allow these regions to etch far more quickly than others. This has spawned the fi eld of glass MEMS devices.…”

Numerical and Experimental Investigation of Morphological Modification on Fused Silica Using CO2 Laser Ablation

“…Laser processing is an effective and attractive method for surface modification of various materials, including surface texturing of semiconductors [1,2], corrosion prevention in biocompatible metals [3,4], and surface polishing of optical glass [5,6]. Employing CO 2 laser melting in a non-evaporative regime has enabled us to obtain surfaces of optical glass with a roughness smaller than 0.1 nm at a rapid processing rate of up to 5 cm 2 /s [5].…”