All-optical control of light on a silicon chip
All-optical control of light on a silicon chip
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DOI：
10.1038/nature02921
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发表时间：
2004-10-28
期刊：
影响因子：
64.8
通讯作者：
Lipson, M
中科院分区：
文献类型：
--
作者：
Almeida, VR;Barrios, CA;Lipson, M
光子电路是开发高度集成的光通信组件的长期目标（1-3），其中光束可以改变其他光束的流向。此外，使用硅——微电子工业的主要材料——作为这种电路的平台是非常可取的。最近已经在硅中证明了弯曲、分裂、耦合和滤光的光子结构（4,5），但是这些结构中的光流是预先确定的，在操作过程中不能轻易调制。全光开关和调制器已经用III-V型化合物半导体证明了（6,7），但由于硅的非线性光学特性相对较弱，在硅中实现同样的功能是具有挑战性的。事实上，硅中的全光开关只能通过在大型或非平面结构中使用极高的功率（8-15）来实现，其中调制光在平面外传播。这种高功率、大尺寸和非平面几何结构不适合进行有效的片上集成。在这里，我们展示了在硅上使用高度限光结构来提高光对折射率微小变化的灵敏度的快速全光开关的实验演示。使用能量低至25 pJ的光脉冲，该结构的传输可以在不到500 ps的时间内被调制高达94%。这些结果证实了最近的理论预测（16），即利用谐振结构在硅中进行有效的光开关。
Photonic circuits, in which beams of light redirect the flow of other beams of light, are a long-standing goal for developing highly integrated optical communication components(1-3). Furthermore, it is highly desirable to use silicon - the dominant material in the microelectronic industry - as the platform for such circuits. Photonic structures that bend, split, couple and filter light have recently been demonstrated in silicon(4,5), but the flow of light in these structures is predetermined and cannot be readily modulated during operation. All-optical switches and modulators have been demonstrated with III-V compound semiconductors(6,7), but achieving the same in silicon is challenging owing to its relatively weak nonlinear optical properties. Indeed, all-optical switching in silicon has only been achieved by using extremely high powers(8-15) in large or non-planar structures, where the modulated light is propagating out-of-plane. Such high powers, large dimensions and non-planar geometries are inappropriate for effective on-chip integration. Here we present the experimental demonstration of fast all-optical switching on silicon using highly light-confining structures to enhance the sensitivity of light to small changes in refractive index. The transmission of the structure can be modulated by up to 94% in less than 500 ps using light pulses with energies as low as 25 pJ. These results confirm the recent theoretical prediction(16) of efficient optical switching in silicon using resonant structures.