A Light Modulator Technology for Spatio-Temporal Coherence Control

光源的时空相干特性在一系列应用中至关重要，包括：1）在高分辨率成像系统中形成显微图像;2）在自由空间光通信中通过大气湍流条件的信号传播;3）在投影和增强现实/虚拟现实显示中生成的图像的质量;4）激光制造和材料加工中的光束传播; 5）光学捕获;6）通过湍流介质成像;7）全息术;8）光学捕获;以及9）非视线成像-“在拐角处看到”。对于许多应用，如果可以以可编程的方式对光源的时空相干特性施加一定程度的控制，使得其可以精确地定制为上述任何应用，则将是有利的。传统的激光源通常表现出高水平的相干性。然而，取决于应用，高空间和/或时间相干性并不总是期望的。尽管可以通过空间或光谱滤波来控制非相干光源的空间和时间相干性，但它们仍然与呈现泊松光子统计而不是玻色-爱因斯坦光子统计的激光器有根本的不同。此外，对于上面列出的许多应用，非相干源要么不适合，要么它们表现出其他特性，例如降低的光谱控制和较差的收集效率，这使得它们不吸引人。使用现成的技术可以实现对时空特性的基本水平的控制，但是这些往往不太理想，因为它们涉及机械移动的部件，不可缩放，并提供对相干程度的有限控制。通常，它们不提供模拟控制，也不与像素化设备架构兼容，这将使得能够精确控制跨光束的相干性。为了真正彻底改变上述应用，并充分利用部分相干的好处，需要一个尚未实现的时空特性的水平控制。对于生物医学成像、通信、AR/VR投影显示和3D激光制造领域的学术研究人员和工业家来说，开发一种能够提供时空特性精细控制的颠覆性新技术将是一个非常令人兴奋的前景。此外，作为一种颠覆性的新技术，它将在应用光学领域实现新的科学发现以及促进生物医学，显示和通信工程的技术突破方面产生相当大的影响。该提案的主要目标是开发一种新的光子技术，该技术将对激光源的时空特性进行前所未有的控制。这项新技术的设计和开发将使其易于在一系列应用中部署，并且它将是电寻址和像素化的，以便可以在整个光束中独立地改变相干特性，从而产生全新的行为和特性。该技术将基于电响应软物质。本文提出的研究提供了一个独特的机会，可以创建一个破坏性的世界领先的相干调制器技术，可以在科学和商业上产生深远的影响，从成像到自由空间可见光通信的应用。该项目的第二个好处是，这种变革性技术的发展将为我们提供一个非常强大的工具，用于研究光学相干性的特性。

The spatio-temporal coherence characteristics of a light source are of critical importance in a range of applications including:1) The formation of microscopic images in high-resolution imaging systems;2) The propagation of signals through atmospheric turbulent conditions in free-space optical communications;3) The quality of images generated in projection and augmented reality/virtual reality displays;4) Beam propagation in laser manufacturing and material processing;5) Optical Trapping;6) Imaging through turbulent media;7) Holography;8) Optical trapping; and9) Non-line of sight imaging - 'seeing around corners'. For many applications it would be advantageous if one could exert a level of control over the spatio-temporal coherence characteristics of the light source in a programmable way so that it could be precisely tailored to any of the applications outlined above. Conventional laser sources typically exhibit a high level of coherence. However, depending on the application, high spatial and/or temporal coherence is not always desirable. Even though it is possible to control the spatial and temporal coherence of incoherent light sources through spatial or spectral filtering, they are still fundamentally different from a laser which exhibits poissonian photon statistics, rather than Bose-Einstein photon statistics. Furthermore, for many of the applications listed above, incoherent sources are either not suitable or they exhibit other properties, such as reduced spectral control and poorer collection efficiency, which makes them unattractive.A rudimentary level of control of the spatio-temporal characteristics can be achieved using off-the-shelf technologies, but these tend to be less than ideal as they involve mechanically-moving components, are not scalable, and offer limited control of the degree of coherence. In general, they do not provide analogue control nor are they compatible with a pixelated device architecture, which would enable precise control of the coherence across the beam. To truly revolutionise the applications described above, and to take full advantage of the benefits of partial-coherence, an as-yet-unrealised level control of the spatio-temporal characteristics is required. The development of a disruptive new technology that would offer fine control of the spatio-temporal characteristics would be an extremely exciting prospect for both academic researchers and industrialists working in the fields of biomedical imaging, communications, AR/VR projection displays, and 3d laser manufacturing. Moreover, as a disruptive new technology it would have considerable impact both in terms of enabling new scientific discoveries in applied optics as well as promoting technological breakthroughs in biomedical, display, and communication engineering. The key objective of this proposal to develop a new photonics technology that would offer unprecedented control of the spatio-temporal characteristics of a laser source. This new technology will be designed and developed to be readily deployable in a range of applications, and it will be electrically addressable and pixelated so that the coherence properties can be altered independently across the light beam, leading to radically new behaviour and characteristics. The technology will be based upon electrically-responsive soft matter. The research proposed herein offers a unique opportunity to create a disruptive world-leading coherence modulator technology that could have far-reaching impact both scientifically and commercially in applications ranging from imaging to free-space visible communications. A secondary benefit of this project is that the development of this transformative technology would provide us with an exceptionally powerful tool with which to study the properties of optical coherence.