Ultra-precision optical engineering with short-wavelength semiconductor disk laser technology

自激光器首次投入使用以来，已经有50年的历史了，但由于激光技术的不断创新，仍然有许多新的应用成为可能。科学家和工程师目前正在开发一系列令人兴奋的光学工程技术，以实现更高的传感，制造和测量精度：从激光图案创建的纳米级晶体结构的制造到原子能级的探测，以定义用于通信和导航的时间和频率标准。这种基于可见光和紫外线（短波长）的研究非常活跃;然而，研究人员目前正在努力，并且不得不变得相当善于用复杂的系统转换当前的激光器，用于光束整形，放大和频率转换，这些系统通常达不到所需的波长，功率和精细度，并将这项技术限制在实验室中。该计划将与这些科学家和工程师合作开发一种新的简化和定制的短波长激光系统，以解决激光工具箱中的空白，显着提高能力，并将这些目前的专业技术从实验室带到广泛部署的技术水平。目标光学工程系统的核心激光技术将是半导体盘激光器（SDLs）。SDL与传统的高性能激光器的不同之处在于增益材料是在纳米尺度上设计的。与激光晶体（毫米长）、染料流或加压气体管不同，光放大由几个量子威尔斯（QW）提供：超薄（几纳米厚）半导体层，相对于激光器中的光场以纳米级精度定位。除了在紧凑性、成本和波长灵活性方面的商业优势外，这种装置从根本上适合于超精密光学工程所需的非常高的相干性、低噪声激光性能。几乎所有的SDL都在光谱的近红外或中红外区域工作;然而，如果它们在可见光和紫外光工作的全部潜力得以实现，将会有更多的应用。Hastie博士的团队在过去5年中开发的短波长SDL的独特功能意味着她现在能够推动该技术以真正的应用为目标，以获得更广泛的利益。她已经确定了英国和国际研究合作伙伴，与英国研究机构的最终用户一起实现可见光和紫外线的高精细度半导体激光系统。光学工程奖将为领导该研究网络和解决已确定的挑战提供必要的平台。最初将针对三种不同的光学工程系统：* 干涉光刻-一种在大面积上制造纳米结构的有效、低成本方法，并广泛用于半导体工业中的电路制造 * 紫外光谱学-用于测量重要的大气痕量气体的浓度 * 光学时钟-用于改进用于通信的时间和频率标准，卫星导航和基础物理测试。这些领域在所需的激光工程和性能方面是互补的，将通过应用短波长SDLs实现能力的逐步变化，并且具有足够的多样性，为积极追求多个有前途的研究方向和应用提供了空间，许多人还没有预测到。

It has been 50 years since the first operation of the laser, yet there are still many new applications being made possible by continued innovation in laser technology. A range of exciting optical engineering techniques are currently being developed by scientists and engineers to achieve ever greater precision in sensing, manufacturing, and measurement: from the fabrication of nanometre-scale crystal structures created by laser light patterns to the probing of atomic energy levels to define the time and frequency standards used for communications and navigation. Such visible- and ultraviolet-based (short wavelength) research is very active; however, investigators are currently making do and having to become rather adept at converting current lasers with complex systems for beam shaping, amplification and frequency conversion which generally fall short of the desired wavelength, power and finesse, and confine this technology to the lab. This programme will develop a new class of simplified and tailored short wavelength laser systems in collaboration with these scientists and engineers in order to address a gap in the laser toolbox, dramatically improve capability, and bring these currently specialist techniques out of the lab to the level of widely deployed technology.The core laser technology for the optical engineering systems targeted will be semiconductor disk lasers (SDLs). SDLs are distinct from conventional high performance lasers in that the gain material is engineered on the nanometre scale. Rather than a laser crystal (millimetres long), a flow of dye, or a pressurised tube of gas, light amplification is provided by several quantum wells (QWs): ultra-thin (few nanometres thick) layers of semiconductor, positioned with nanometre-scale accuracy with respect to the light field in the laser. Aside from commercial advantages in terms of compactness, cost and wavelength flexibility, this set-up is fundamentally suited to the very high coherence, low noise laser performance required for ultra-precision optical engineering.Nearly all SDLs operate in the near- or mid-infrared regions of the spectrum; however, many more applications will open up if their full potential for visible and ultraviolet operation is realised. The unique capability in short wavelength SDLs that Dr. Hastie's team has developed over the past 5 years means that she is now in a position to push the technology to target genuine applications for wider benefit. She has identified UK and international research partners for the realisation of high finesse semiconductor laser systems in the visible and UV, together with end users at research institutions in the UK. The Challenging Engineering award will provide the platform necessary to lead this research network and address the identified challenges.Three different optical engineering systems will be targeted initially:* interference lithography - an effective, low-cost method of fabricating nanostructures over a large area and widely deployed in the fabrication of circuits in the semiconductor industry* ultraviolet spectroscopy - for measuring the concentrations of important atmospheric trace gases* optical clocks - for the improvement in time and frequency standards used for communications, satellite navigation and testing of fundamental physics.These areas are complementary in terms of the required laser engineering and performance, will achieve a step-change in capability through the application of short wavelength SDLs, and are sufficiently diverse to provide scope to actively pursue multiple promising research directions and applications, many not yet predicted.