Raman-converted Kilowatt-class ultrafast laser Solutions for microexplosion-based Silicon transformations and new 3D manufacturing technologies

紧密聚焦的超短激光脉冲可以在物质中引发受限的微爆炸，导致具有极端压力（>10 TPa）和温度（> 105 K）的强烈非平衡条件，即远远超过其他技术可以实现的条件。最近，通过将固体转化为具有独特性能的超致密晶相，这使得材料科学的突破成为可能。这项研究还包括当前的工业过程，如激光加工，因为相同的过程可以用来创建固体表面下的任何3D结构。然而，迄今为止，所有这些进展仍然局限于透明的网络。试图将激光诱导的微爆炸效应转化为体硅的尝试已经失败，因为非线性过程强烈限制了可以传递到窄带隙材料中的强度。通过新的相互作用方案和新型高功率激光解决方案的开发，KiSS项目旨在进入硅内部的微爆炸状态。KiSS将利用千瓦级超快激光器的出现来展示单晶金刚石中的高效拉曼转换，以提供在硅的透明域（1420 nm）中发射的> 100 W级系统。所提出的技术的独特特征是在该光谱区域中在高功率下的高通用性。实施的系统将集成脉冲的时间和偏振整形，以便可以精确调整光束特性（按需），以满足半导体内部3D加工的严格要求。在相互作用研究的前沿，将开发一种新的交叉光束激光装置，以增强材料内部的条件。我们提出的发展，其中紧密集中的反向传播脉冲有助于相互作用。对同步和每个贡献脉冲的特性的严格控制提供了新的自由度和优化。这一概念将通过对硅内部深处前所未有的微爆炸条件进行时间分辨研究来验证。拟议的发展将导致一个具有大容量处理能力的实用解决方案。最后一个演示器在国际上是独一无二的，它将为通过激光驱动的微爆炸对物质进行普遍探索开辟新的和令人兴奋的机会。这将得到一项合作工作（澳大利亚国立大学）的支持，其中加工硅的结构诊断将在立方毫米数量级的体积中成为可能。从长远来看，控制合成新的致密硅相将对技术产生非凡的影响。我们还预计开发的高通量制造技术的短期或中期工业相关性。这将通过硅芯片内部微流体冷却回路的首次直接写入演示来展示。

Tightly focused ultrashort laser pulses can induce confined micro-explosions in matter that lead to strong non-equilibrium conditions with extreme pressures (>10 TPa) and temperatures (> 105 K) i.e. well beyond what can be achieved by other techniques. Recently, this has made possible a breakthrough in material science by transformation of solids into super-dense crystalline phases exhibiting unique properties. This research also encompasses current industrial processes such as laser machining because the same process can be used to create any 3D structures beneath the surface of solids. However, all these advances so far remain limited to transparent dielectrics. Attempts to translate the laser-induced micro-explosion effect into bulk silicon have failed because of nonlinear processes that strongly limit the intensity that can be delivered into materials with narrow bandgap. By joint efforts on new interaction schemes and the development of novel high-power laser solutions, the project KiSS aims at accessing the micro-explosion regime inside silicon. KiSS will capitalize on the advent of kW-class ultrafast lasers to demonstrate efficient Raman conversion in single-crystal diamond to provide >100W-class systems emitting in the transparency domain of silicon (1420 nm). A unique feature with the proposed technology is a high versatility at high power in this spectral region. The implemented system will integrate temporal and polarization shaping of the pulses so that the beam characteristics beams can be precisely adjusted (on-demand) to meet the severe requirements identified for 3D processing inside semiconductors. On the front of the interaction studies, a novel crossed-beam laser arrangement to enhance the conditions inside the material will be developed. We propose developments in which tightly focused counter-propagating pulses contribute to the interaction. Tight control of synchronizations and characteristics of each contributing pulse provide new degrees of freedom and optimization. The concept will be validated by time-resolved studies of unprecedented micro-explosion conditions achieved deep inside silicon. The proposed developments will lead to a practical solution with large volume processing capabilities. The final demonstrator, unique at the international level, will open up new and exciting opportunities for generalized explorations of the matter by laser-driven micro-explosions. This will be supported by a collaborative work (Australian National University) in which structural diagnostics of processed silicon will become possible in a volume of the order of cubic millimeter. At long term, the controlled synthesis of new dense phases of silicon will have an extraordinary impact on technologies. We also expect short or mid-term industrial relevance of the developed high-throughput manufacturing technology. This will be shown by the first direct writing demonstrations of microfluidic cooling circuits inside silicon chips.