Low-cost, High-performance Lasers: Novel Applications of Disk Laser Approaches

近年来在世界各地的实验室中开发的尖端激光系统并不需要性能。例如，基于掺杂钛的蓝宝石晶体的激光器现在通常产生十亿分之几秒的脉冲：最短的人造事件。在这短短的几分之一秒内，激光的功率相当于一个发电站的输出。当今高性能激光器的这些和其他极端规格使其成为潜在的革命性工具。事实上，在科学和工程领域，这场革命已经开始，允许对非常小、非常快和非常复杂的东西进行详细研究。然而，潜力更大。今天的高性能激光器还不是科学家口袋里的小刀;笨重而昂贵的泰坦被束缚在激光实验室里。激光工程的挑战是在实际的封装中利用这种性能和功率，这样激光就可以到达用户那里，而不是用户必须来到激光器那里。这将引发第二次--也可能是更大的--应用程序革命。我们相信，使用激光材料的圆盘，而不是传统的棒，可以为高性能激光器的文明做出巨大贡献。这主要有两个原因。首先，激光材料的许多重要但有害的性质随长度而变化;这些问题可以通过使用薄圆盘来最小化。其次，精细激光器，例如基于钛蓝宝石的激光器，通常由其他激光器泵浦;由于所需的性能水平，这些泵浦激光器可能花费数万英镑。盘的使用降低了所需的泵浦光束的质量;因此，我们相信较低成本的器件，例如激光二极管甚至LED可以与传统上需要高成本泵浦激光器的激光系统一起使用。偶然地，用于下一代DVD的蓝色激光二极管和用于固体激光器的高功率发光二极管（LED）的发展，固态照明已经导致这些光源的性能的显著改进。由于这些设备面向大众市场，单位成本将很小，使其成为理想的低成本泵源。即使有了这些改进，这种光源也缺乏泵浦传统精细激光器的功率和光束质量。然而，磁盘的几何形状消除了这些障碍，使我们相信，第一次演示的二极管激光泵浦钛：蓝宝石和新一代的LED泵浦激光器。这些都是潜在的颠覆性技术。更低成本、更紧凑的钛宝石激光器将直接将这一纯种激光系统的优势应用于应用，而低成本LED泵浦激光器将使需要精细激光器但不可避免会出现损失或损坏的应用成为可能，如高风险海底或有毒物质检测。

The cutting edge laser systems that have been developed in laboratories around the world in recent years do not want for performance. For example, lasers based on crystals of sapphire doped with titanium now routinely produce pulses of a few millionths of a billionth of a second: the shortest of man-made events. For that tiny fraction of a second, the power of the laser light is the equivalent the output of a power-station. These and other extreme specifications of today's high performance laser make them potentially revolutionary tools. Indeed, across science and engineering that revolution has started, allowing the very small, the very fast and the very complex to be studied in detail. The potential, however, is greater still. Today's high performance laser is not yet the penknife in the scientist's pocket; unwieldy and expensive, the titan is chained to the laser lab. The laser engineering challenge is to harness this performance and power in a practical package, such that the laser can go to the user rather than the user having to come to the laser. This will trigger a second - and arguably bigger - applications revolution. We believe that the use of a disk of laser material, rather than the conventional rod, can make a large contribution to civilising high-performance lasers. There are essentially two reasons for this. First, a number of important - but detrimental - properties of laser materials scale with length; these problems can be minimised by using thin disks. Second, finesse lasers, such as those based on titanium sapphire, are typically pumped by other lasers; these pump lasers can cost tens of thousands of pounds due to the performance levels required. The use of disks reduces the quality of the pump beam that is needed; thus, we believe lower cost devices such a laser diodes and even LEDs can be used with laser systems that have traditionally required high cost pump lasers.Serendipitously, the development of blue laser diodes for next generation DVD and high power light emitting diodes (LEDs) for solid-state lighting has led to a considerable improvement in performance of these light sources. As these devices are aimed at mass markets, the unit costs will be small, making them ideal low-cost pump sources. Even with these improvements, such light sources lack the power and the beam quality to pump conventional finesse lasers. However, disk geometries remove these hurdles enabling, we believe, the first demonstration of diode-laser pumping of Ti:sapphire and a new generation of LED pumped lasers. These are potentially disruptive technologies. Lower-cost, more compact Ti:sapphire lasers will take the benefits of this thoroughbred laser system directly to the application and low-cost LED pumped lasers will enable applications - like high-risk undersea or toxic substance sensing - that required finesse lasers but where loss or damage is inevitable.