Controlling nano to microscale dynamics with light: from fundamental research to advanced fabrication

我们必须向一个更可持续的社会转型。先进材料和新的制造方法将在发展可再生能源和减少影响的高科技制造工艺的努力中发挥核心作用。我们将使用光作为探测器，也作为替罪羊，在微米和纳米尺度上研究、控制和制造系统。我们的研究遵循两个主要推动力： A)激光被用来精确切割从汽车到智能手机的各种消费品。即使取得了这样的成功，要生产出具有特定3D形状的产品，人们也必须求助于更浪费和更不精确的工具，因为激光无法在飞行中停止。由于NSERC DG的资助，我们能够发明一种新技术来控制激光在从钢到骨的任意材料中的穿透深度。我们将应用这一潜在的变革性技术来改进高功率激光焊接，并制造出亚微米级精度的新型人工材料。我们的结果将减少制造时间，帮助加拿大的汽车、微电子和航空航天行业。更重要的是，主动深度控制可能会为目前遥不可及的全新方法或材料打开激光加工的大门。 B)在典型的太阳能电池中，来自太阳的一个光子激发电池中的一个电子。最近，理论家们预测，我们可以将碳这种最具环境吸引力的材料的电子转换效率提高一倍，形成纳米管。尽管碳纳米管太阳能电池的潜力是巨大的，但挑战是巨大的。我们需要了解它们的基本性质，才能使它们成为一个新的光电子产业的基石。这项工作的一个重要组成部分是跟踪电子在微小的纳米直径管中的诞生和运动，时间分辨率极高，只有使用超快光学才能做到。 这项研究的一个重要组成部分是对拥有尖端光学工具、新材料、纳米表征和先进制造的学生的贡献和培训。

We must transform to a more sustainable society. Advanced materials and new manufacturing methods will play a central role in the effort to develop renewable energy sources and reduced-impact high tech fabrication processes. We will use light as a probe and also as a scapel, to study, control and fabricate systems on the micro and nanoscale. Our research follows two main thrusts: A) Lasers are used to precision cut a wide range of consumer products, from cars to smartphones. Even with such success, to produce a product with a specific 3D shape, one must resort to more wasteful and less precise tools since a laser beam cannot be stopped in mid-flight. Due to NSERC DG funding, we were able to invent a novel technique to control laser penetration depth in arbitrary materials, ranging from steel to bone. We will apply this potentially transformative technology to improve high power laser welding and fabricate new artificial materials with submicron precision. Our results will reduce manufacturing time, helping the Canadian automotive, microelectronics and aerospace industries. More importantly, active depth control may open laser processing to completely new approaches or materials that are currently out of reach. B) In a typical solar cell, one photon from the sun excites one electron in the cell. Recently, theorists have predicted that we can double the electron conversion efficiency in one of the most environmentally alluring materials, carbon, in the form a nanotube. Though the potential of carbon nanotube solar cells is huge, the challenges are immense. We need to understand their basic fundamental properties for them to serve as a building block for a novel opto-electronic industry. An important component of this effort is to track the birth and motion of electrons in the tiny nm-diameter tubes with extreme high time resolution only possible with ultrafast optics. An essential component of this research is the contributions and training of students with sophisticated optical tools, novel materials, nano-characterization and advanced manufacturing.