NER: Nanofabricated Optical Devices Based On Single Photon Tunneling

该提案是对NSF 01-157类纳米科学与工程倡议的响应。最近，我们在测量覆盖着一层聚二乙炔的厚金膜中通过单个亚波长针孔的光隧道时，获得了单光子隧道效应的强有力证据，这是单电子隧道效应的直接模拟。由于聚二乙炔的光学非线性，在每秒几千个光子的非常低的光强下，一些针孔的传输达到饱和。这一结果与单电子隧穿实验中观察到的库仑阻塞现象类似，从理论上解释了这一现象。单光子隧穿效应可能在量子通信和信息处理等新兴领域得到广泛应用。到目前为止所报道的实验是针对自然存在于金属薄膜中的随机针孔进行的。对于在受控条件下产生这种效应所需的针孔的形状和大小没有详细的了解，这严重限制了这种效应的理论描述及其可能的应用的进展。我们建议扩展这些实验，利用离子束研磨制造技术来研究控制良好的几何结构中的单光子隧穿效应。基于这项研究，我们将在光通信和量子光学领域探索一些新的器件想法。

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NER. Strong evidence of a single-photon tunneling effect, a direct analog of single-electron tunneling, has been obtained recently in our measurements of light tunneling through individual subwavelength pinholes in a thick gold film covered with a layer of polydiacetylene. The transmission of some pinholes reached saturation because of the optical nonlinearity of polydiacetylene at a very low light intensity of a few thousands photons per second. This result has been explained theoretically in terms of "photon blockade", similar to the Coulomb blockade phenomenon observed in single-electron tunneling experiments. The single-photon tunneling effect may find many applications in the emerging fields of quantum communication and information processing. The experiments reported so far have been performed for random pinholes that are naturally present in thin metal films. There is no detailed knowledge on the shape and size of the pinholes necessary to produce this effect under controlled conditions, which severely limits advancement of the theoretical description of the effect and its possible applications. We propose to expand these experiments to study single-photon tunneling effect in well-controlled geometries, by making use of ion-beam milling fabrication techniques. Based on this research we are going to explore a number of novel device ideas in the areas of optical communications and quantum optics.