The Physics of Polymer Photonic Devices: Experiment and Theory

在过去的十年中，在用柔性塑料材料制造LED和激光器等光源方面取得了显着进展。这具有广泛的潜在应用，例如卷起电视显示器或将数据通信系统编织到您的衣服中。聚合物LED的技术现在已经成熟到塑料发光显示器可作为商业产品的程度。塑料激光器、光放大器和其他光子器件的发展要差得多。但这些提供了巨大的潜力，作为复杂的，但廉价的，可见光光源。我们现在已经达到了一个阶段，我们已经在实验室中证明了这种潜力，为了向实际设备迈出下一个重要的一步，我们迫切需要在微观水平上更深入地了解这些材料的行为。聚合物链如何与强光相互作用的物理学涉及竞争过程的丰富组合。这些过程在设备中的累积效应尚未得到很好的理解。该提案旨在通过汇集两组专家的专业知识来发展这种理解：一组是测量这些聚合物的光学性能及其在光子学中的应用的专家，另一组是光学材料理论的专家。通过理论和实验的结合，我们的目标是了解半导体聚合物的复杂光学相互作用，并以新的和更复杂的方式利用它们。这将有助于我们优化当前设备的性能（例如速度和效率）;但更重要的是，它将使基于这些材料的新一代光子设备成为可能。我们将对这些聚合物在设备条件下如何对光做出响应进行光学测量。通过这样做，我们可以理解，例如，增加激光所需功率的损耗机制，或者限制脉冲持续时间及其传播的过程。利用量子力学，我们还可以模拟产生这些效应的微观物理。然后，我们可以尝试使用我们的新知识来减少损失并改善操作。这种将微观量子理论与实验相结合的方法以前曾被用来大大改善无机半导体器件。事实证明，它对优化无机二极管激光器的发展至关重要，例如用于DVD播放机和激光打印机的激光器。通过汇集互补的专业知识，我们希望建立对有机半导体的新的理解水平。为了证明我们的方法的优点，我们将进行两项试验研究。首先，我们将开发光开关，我们可以使用一个光脉冲通过或阻止另一个脉冲的传播。为了使这样的设备工作良好，我们将需要一个非常快的过程，可以在开和关状态之间干净地切换，同时不扭曲传播的光脉冲-因此，对材料物理的良好理解将是必不可少的。在第二项试点研究中，我们将观察和探索一种称为慢光的奇异现象，这种现象以前曾在无机半导体中发现过。这种效应延迟了光通过材料的传播，并且可能在未来形成光学信号处理器的基础。该模型还将能够指导和通知许多其他复杂光子器件的设计，包括短脉冲塑料激光器，光学放大器和探测器;未来塑料光子系统的所有关键组件。

Remarkable progress has been made over the last decade in making optical sources such as LEDs and lasers out of flexible, plastic materials. This has a wide range of potential applications, such as roll up TV displays or having data communications systems woven into your clothing. The technology of polymer LEDs has now matured to the degree that plastic light-emitting displays are available as commercial products. Plastic lasers, optical amplifiers and other photonic devices are much less well developed. But these offer huge potential as sophisticated, yet inexpensive, visible light sources. We have reached a stage now where we have demonstrated this potential in the laboratory, and in order to take the next major step forward to practical devices we urgently need a deeper understanding of the behaviour of these materials at the microscopic level. The physics of how the polymer chains interact with intense light involves a rich combination of competing processes. The cumulative effect of these processes in devices is not yet well understood. This proposal seeks to develop this understanding by bringing together the expertise of two groups: one who are experts in measuring the optical performance of these polymers and in their application for photonics, and the other who are experts in the theory of optical materials. Through a combination of theory and experiment we will aim to understand the complex optical interactions of semiconducting polymers, and exploit them in new and more sophisticated ways. This would help us to optimise the performance (e.g. speed and efficiency) of current devices; but more significantly it would enable a new generation of photonic devices based on these materials. We will make optical measurements of how these polymers respond to light under device conditions. By doing this we can understand, for example, the loss mechanisms that increase the power required by a laser, or the processes that limit pulse durations and their propagation. Using quantum mechanics we can also simulate the microscopic physics which gives rise to these effects. We can then try to reduce the losses and improve operation, using our new knowledge. This approach of combining a microscopic quantum theory with experiment has previously been used to greatly improve inorganic semiconductor devices. Indeed it proved crucial to the development of optimised inorganic diode lasers such as those used in DVD players and laser printers. By bringing together complementary expertise, we hope to build a new level of understanding of organic semiconductors. To demonstrate the advantages of our approach, we will undertake two pilot studies. First we will develop optical switches with which we may use one light pulse to pass or block the propagation of another pulse. For such a device to work well, we will need a very fast process that can switch cleanly between on and off-states, while not distorting the propagating light pulses- a good understanding of the material physics will therefore be essential. In the second pilot study, we will aim to observe and explore an exotic phenomenon known as slow light , which has previously been found in inorganic semiconductors. This effect delays the propagation of light through a material, and may in the future form a basis for optical signal processors. The model will also be able to guide and inform the design of many other sophisticated photonic devices, including short-pulse plastic lasers, optical amplifiers and detectors; all key components of plastic photonic systems of the future.