Ultrafast optical control in semiconductor

我们今天享受的生活水平很大程度上归功于我们对自然世界的理解以及我们将这种理解应用于技术的尝试。在某些情况下，我们努力超越自然所能提供的，并开发新材料或工艺，以推动技术进步，造福社会。 我们的研究计划试图进一步利用光在信息和光子技术。加拿大是这一领域的领导者之一，大大小小的公司提出和推销新的方法来增加互联网的容量或加强通信和其他信息服务。除了帮助满足广泛的光电子工业部门对训练有素的人力资源的需求外，像我们这样的大学团体还研究下一代光学技术的新思路。 我们专注于与控制光和半导体如何相互作用有关的两个方面。在第一个推力中，我们使用激光辐射的相干性或相位特性来直接控制电荷和自旋电流的幅度和方向，将这些电流放置在我们想要的地方，以及我们想要它们的时候，时间尺度短至飞秒，即百万分之几的百万分之一秒。这些技术可能允许开发新类型的信息加密和量子信息处理。 另一个重点是利用纳米结构的半导体来控制光线。 通过改变传输光的材料的结构，可以控制脉冲如何传播，光如何用于切换或路由其他光脉冲，以及控制光脉冲在芯片上移动的速度。 例如，关于光移动有多快，虽然已知在某些情况下没有东西比光传播得更快，但是基于光的信息可能使通信系统过载。光缓冲器或存储设备需要“慢”光来控制信息流。 问题是这样做的方式，允许支持高速通信系统的短光脉冲被延迟可调的量，而不会打破脉冲。

The standard of living that we enjoy today is largely due to our understanding of the natural world and our attempts to apply that understanding in technology. In some cases we strive to surpass what nature has to offer and develop new materials or processes to advance technology for the benefits of society.        Our research program attempts to further the use of light in information and photonic technologies. Canada is one of the leaders in this area with large and small companies proposing and marketing new ways to increase the capacity of the internet or enhance communication and other information services. Besides helping to satisfy demands for trained manpower in the broad photonics industrial sector, university-based groups such as ours investigate new ideas for the next generation of optical technology.       We focus on two thrusts related to gaining control of how light and semiconductors interact. In the first thrust, we use the coherence or phase property of laser radiation to directly control the amplitude and direction of charge and spin currents, placing these currents where we want them and when we want them, on time scales as short as femtoseconds, i.e. thousands of millionths of millionths of a second. These techniques might allow for the possible development of new types of information cryptography and quantum information processing.       The other thrust employs nanostructed semiconductors to control light.  By varying the architecture of materials that transmit light one can control how pulses propagate, how light can be used to switch or rout other light pulses, and, also control how fast light pulses move on a chip.  For example, with respect to how fast light moves, while it is known that nothing travels faster than light in some cases light based information, can overload a communications system. "Slow" light is required for optical buffers or storage devices to control the flow of  information.  The problem is to do so in a manner that allows the short optical pulses that underpin high speed communications systems to be delayed by adjustable amounts without the pulses breaking up.