Modular Ultrafast Sources

自1990年研制出第一个克尔透镜锁模激光器以来，各种配置的实用飞秒激光器已经为许多重大科学发展提供了可观的帮助。必须认识到，应用空间仍然受到当前一代超快激光器的成本、复杂性、熟练用户要求和有限灵活性的限制。在这个拟议的联合项目中，我们寻求引领新一代超快激光器的发展。通过采用模块化方法进行激光设计，我们的目标是展示一个平台，从该平台可以设计激光器，以满足广泛的用户特定要求。例如，采用这种方法，用于通信的激光器将具有必要的高重复率和低峰值功率，而对于生物光子学，将提供高峰值功率以充分利用可开发的光学非线性。我们计划使用本体和波导几何形状的振动晶体以及半导体量子点结构作为主要增益介质。虽然振动晶体在超短脉冲激光器中得到了广泛应用，但传统激光器设计的灵活性非常有限。为了纠正这种情况，我们打算彻底改变腔设计，使激光输出参数的电气控制成为可能。例如，我们希望为用户提供一种方法，使其在轻击开关时从非模型锁定状态更改为飞秒脉冲状态。此外，通过利用振动晶体中的波导，我们相信我们可以推出新一代高度紧凑的激光器，将半导体激光器的许多优点与晶体基器件的最具吸引力的特征结合起来。在超快光子学合作的一些初步工作中，我们已经展示了半导体量子点结构作为宽带增益介质的潜力，可以支持放大和产生飞秒光脉冲。我们现在寻求在这些有希望的结果的基础上，推动真正灵活的超快激光器，这种激光器将适用于外部电子控制增益和损耗元件。进展有望导致新一代激光器，可以提供的应用兼容性远远超过传统的激光系统设计。在这一战略中，我们计划采用混合方法，将半导体激光器的优点与晶体的能量存储能力相结合，提供紧凑而坚固的光源，其脉冲特性涵盖了一系列持续时间、能量和剖面。这个项目的一个主要部分将致力于开发超快激光器的控制功能。其目的是使用腔内元件的直接电气控制，为脉冲整形、调制数据流、波长调谐和定制色散提供设计选项。为了确保这项研究是适用的，我们将在一组确定的示威者的背景下评估激光的发展。这些实现将用于展示设计灵活性如何为生物、医疗、通信和相关应用提供优化的激光器。我们组建了一支专业互补的研究团队，并在光子学领域建立了国际卓越的业绩记录。这个项目作为一个整体将由圣安德鲁斯大学管理，但所有三个研究小组将对激光发展的各个方面进行互动研究。我们相信，这个团队的工作将代表前沿的基础和转化研究，它应该代表英国在发展新的超快激光器方面的世界领先优势。

Since the development of the first Kerr-lens mode-locked lasers in 1990, practical femtosecond lasers in a wide variety of configurations have delivered handsomely to a significant number of major scientific developments. It has to be recognised that the application space remains limited by the cost, complexity, skilled-user requirements and restricted flexibility of the current generation of ultrafast lasers. In this proposed joint project we seek to lead the way in the development of a new generation of ultrafast lasers. By adopting a modular approach for laser design we are aiming to demonstrate a platform from which lasers can be designed to address a wide range of user-specific requirements. By taking this approach, lasers for use in communications, for example, will have the necessary high repetition rates and low peak powers whereas for biophotonics high peak powers will be delivered to take full advantage of exploitable optical nonlinearities. We plan to work with vibronic crystals in both bulk and waveguide geometries and semiconductor quantum dot structures as the primary gain media. Although vibronic crystals have been deployed widely in ultrashort-pulse lasers the flexibility offered by conventional laser designs is very limited. To remedy this situation we intend to revolutionise cavity design to enable electrical control of the laser output parameters. For example, we wish to provide a means to users to change from an unmodelocked status to a femtosecond-pulse regime at the flick of switch. Also, by exploiting waveguiding in vibronic crystals we are confident that we can introduce a new generation of highly compact lasers that will combine many of the advantages of a semiconductor laser with the most attractive features of crystal based devices. In some preliminary work in the Ultrafast Photonics Collaboration we have shown the potential of semiconductor quantum dot structures as broadband gain media that Can support the amplification and generation of femtosecond optical pulses. We now seek to build on those promising results and make the push towards truly flexible ultrafast lasers that will be amenable to external electronic control of the gain and loss components. Progress is expected to lead to a new generation of lasers that can give applications compatibility that far exceeds that available from traditional laser system designs. Within this strategy we plan to employ hybrid approaches where the benefits of semiconductor lasers will be combined with the energy storage capabilities of crystals to deliver compact and rugged sources having pulse characteristics that cover a range of durations, energies and profiles.A major part of this project effort will be devoted to the development of control functionality in ultrafast lasers. The intention is to use direct electrical control of intracavity components to deliver designer options for pulse shaping, modulated data streams, wavelength tuning and tailored dispersion. To ensure that this research is applicable we will evaluate the laser developments in the context of a set of identified demonstrators. These implementations will be used to show how design flexibility can deliver optimised lasers for biological, medical, communications and related applications.We have put together a research team having complementary of expertise and established track records of international excellence in photonics. This project as a whole will be managed from St Andrews University but all three research groups will undertake interactive research on all aspects of the laser development. We are confident that the work of this team will represent cutting-edge fundamental and translational research and it should represent a world leading strength for the UK in the development of new ultrafast lasers.