Mid-Infrared photonic sources and devices

中红外光谱区(MID-IR)包含了最常见的分子(甲烷、臭氧、水、二氧化碳等)的强烈振动跃迁，是最近出现的具有极其重要科学和技术意义的光谱区。然而，毫不奇怪，中红外激光光源以及相应的传输和处理设备(例如，波导、传感器等)已经证明了它们对于光谱学、材料加工和生物分子传感等几个应用是多么关键。许多环境(远程蒸气痕迹探测)、安全(导弹对抗)和通信(隐蔽通信系统)应用也可以受益于覆盖3-5微米和8-13微米两个大气传输窗口的中红外光源。目前，中红外光源、元器件和器件的发展面临着一些需要解决的实际和根本性的挑战。因此，这项建议的主要目标是专门解决与中红外光纤激光器和中红外集成光子组件的发展有关的基本挑战。*为了实现这一目标，我们将利用光子学使现在可以通过非线性激光物质相互作用来改变材料属性的事实。事实上，飞秒脉冲具有完美地控制透明材料精确区域上的能量沉积速率的能力，从而非常精确地改变其物理和光学性质。这对各种新的加工工艺至关重要，例如在玻璃中刻写波导或反射结构；将透明介质材料焊接在一起或与其他材料如晶体(蓝宝石、钻石、YAG、ZnSe等)焊接。或金属；电介质材料的精确切割或穿孔。现在，很明显，对于工作在中红外光谱区域的材料和设备来说，这种光致3D光子组件的飞秒刻字的整个潜力还没有得到探索。按照这一思路，我们的研究活动将是定向的，尽管我们的发现基金的目标主要是解决此类发展背后的基本方面，但其结果可能会产生重大的社会经济影响，即在生物医学、电信以及国防和安全方面。*

The middle infrared spectral region (mid-IR) which is comprising the strong vibrational transitions of most common molecules (methane, ozone, water, CO2, etc), has emerged recently as a spectral region of utmost scientific and technological importance. Not surprisingly though, mid-IR laser sources as well as corresponding transmitting and processing devices (e.g. waveguides, sensors, etc.) have proven how crucial they are for several applications, namely in spectroscopy, material processing and bio-molecular sensing. Numerous environmental (remote vapour trace detection), security (missile countermeasures) and communication (covert communication systems) applications could also benefit from mid-IR sources that cover the two atmospheric transmission windows of 3-5 microns and 8-13 microns. Now, the development of mid-IR sources, components and devices is facing several practical and fundamental challenges that need to be addressed. The main objective of this proposal is therefore specifically to address those fundamental challenges pertaining to the development of both mid-IR fiber lasers and mid-IR integrated photonic components.****In order to meet this objective we will take advantage of the fact that photonics makes it now possible to modify material properties through nonlinear laser matter interaction. As a matter of fact, femtosecond pulses possesses the ability to perfectly control the energy deposition rate on a precise area of a transparent material and therefore to alter their physical and optical properties very precisely. This is crucial to a variety of new processes such as the inscription of waveguiding or reflecting structures in glass; the welding transparent dielectric materials together or with other materials such as crystals (sapphire, diamond, YAG, ZnSe, etc.) or metals; the precise cutting or piercing of dielectric materials. Now, it clearly appears that the whole potential of the femtosecond inscription of such photoinduced 3D photonic components have not yet been explored for materials and devices operating in the mid-IR spectral region. This is along this line that our reseach activity will be oriented and although the objective of our discovery grant is primarily to address the fundamental aspects underlying such development, its outcome are likely to have a significant socio-economic impact, namely in biomedicine, telecommunications and defense&security.***