Ultrafast optical control in semiconductor

我们今天享受的生活水平很大程度上是由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，我们努力超越大自然所提供的，开发新的材料或工艺来推进技术，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，大大小小的公司都在提出和推广增加互联网容量或加强通信和其他信息服务的新方法。除了帮助满足广泛的光电子工业部门对训练有素的人力的需求外，像我们这样的大学团体还研究下一代光学技术的新想法。我们专注于光与半导体如何相互作用的控制。在第一次推力中，我们利用激光辐射的相干性或相位特性直接控制电荷和自旋电流的振幅和方向，将这些电流放置在我们想要的地方和我们想要的时间，时间尺度短至飞秒，即百万分之一秒的千分之一。这些技术可能使新型信息密码学和量子信息处理的发展成为可能。另一种推力采用纳米结构半导体来控制光线。通过改变传输光的材料结构，人们可以控制脉冲的传播方式，光如何被用来切换或路由其他光脉冲，还可以控制光脉冲在芯片上移动的速度。例如，关于光的移动速度，虽然我们知道没有什么比光传播得更快，但在某些情况下，基于光的信息会使通信系统过载。光缓冲器或存储设备需要“慢”光来控制信息流。问题在于，如何在不破坏高速通信系统的情况下，将支撑高速通信系统的短光脉冲延迟到可调的幅度。

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.