3D Manufacturing of Glass Microstructures Using Femtosecond Laser

Abstract

The rapid expansion of femtosecond (fs) laser technology brought previously unavailable capabilities to laser material processing. One of the areas which benefited the most due to these advances was the 3D processing of transparent dielectrics, namely glasses and crystals. This review is dedicated to overviewing the significant advances in the field. First, the underlying physical mechanism of material interaction with ultrashort pulses is discussed, highlighting how it can be exploited for volumetric, high-precision 3D processing. Next, three distinct transparent material modification types are introduced, fundamental differences between them are explained, possible applications are highlighted. It is shown that, due to the flexibility of fs pulse fabrication, an array of structures can be produced, starting with nanophotonic elements like integrated waveguides and photonic crystals, ending with a cm-scale microfluidic system with micro-precision integrated elements. Possible limitations to each processing regime as well as how these could be overcome are discussed. Further directions for the field development are highlighted, taking into account how it could synergize with other fs-laser-based manufacturing techniques.

Nanoscale-Precision Removal of Copper in Integrated Circuits Based on a Hybrid Process of Plasma Oxidation and Femtosecond Laser Ablation

“…Nevertheless, it decreases to 0.53 J/cm 2 as more pulses and laser energy are deposited per unit area, which indicates an accumulative behavior. A major factor in the formation mechanisms of the periodic surface structures observed in Figure 3b is considered to be the interference caused by an incident laser beam with the laser-excited surface plasmon wave [21]. In addition, its period has obvious wavelength-dependent characteristics (slightly smaller than the incident laser wavelength), which is in good agreement with the experimental results [38].…”

“…The ablation mechanism of the fs-laser is different from that of traditional long-pulse lasers and there is a strong nonlinear effect in the interaction between the fs-laser and materials. The interaction time between the fs-laser and metal is less than the coupling time between the electron and lattice subsystems, so the extremely unbalanced state in the fs-laser ablation can be analyzed using a TTM that describes the interaction among the laser, electron, and lattice systems [21,25].…”

“…Femtosecond laser (fs-laser) ablation has been demonstrated as an effective means for the micromachining and surface modification of solid materials because of its high machining accuracy, low cost, small heat-affected zone, and controllable and noncontact characteristics, which has been widely used in the field of Cu micromachining [20][21][22]. For example, many studies have been made on welding [23], drilling [24], cutting [25], and surface modification [26][27][28] by the fs-laser.…”

Potential of CO2-laser processing of quartz for fast prototyping of microfluidic reactors and templates for 3D cell assembly over large scale

“…Additionally, it allows high geometrical freedom, high lateral and vertical resolution, fast laser processing of the material without contacting it, the formation of patterns (including channels) with different depth and width, processing of thicker materials in a reasonable time scale (less than 24 ​h), large substrate area processing, mass production of custom-designed features with precise alignment and length-scale from μm to nm and laser engraving in ambient air (no controlled environment needed) [ 20 , 24 ]. Glass micromachining can be accomplished based on a wide range of wavelengths (ultraviolet to infrared) and pulse width (micro-to femtosecond) [ [26] , [27] , [28] , [29] , [30] ]. The primary requirement to be fulfilled for successful laser ablation-induced machining is strong absorption of the material to be processed at the laser operating wavelength, with micrometer-scale absorption depth in the material.…”

Editorial for the Special Issue on New Trends and Applications in Femtosecond Laser Micromachining

“…This Special Issue is composed of 10 contributions, including original research and reviews. The review paper from Butkute et al [2] reports a brief but exhaustive overview of the significant advancements in the femtosecond laser machining of glasses, reviewing the possible modifications of the material and highlighting application examples such as optical waveguiding and microfluidic systems. Following the unique capabilities of femtosecond laser technologies, we highlight four macro areas of applications in which we classified the contributions of the issue.…”