Introduction
Surface plasmon polariton(SPP) is a surface electromagnetic wave coupling to the free electron oscillations in a metal. It can be excited when a light wave strikes a metal film under appropriate conditions. Such SPPs are involved in a wide range of phenomena, including nanoscale optical waveguiding, perfect lensing, extraordinary optical transmission, subwavelength lithography and ultrahigh-sensitivity biosensing. It is also proved experimentally that SPPs are also useful in the investigation of quantum information. We are doing experiments about the quantum optics with SPPs.
Highlights
Plasmon assisted transmission of high dimensional orbital angular momentum entangled state. We present experimental evidence that high dimensional orbital angular momentum entanglement of a pair of photons can be survived after a photon-plasmon-photon conversion. The information of spatial modes can be coherently transmitted by surface plasmons. This experiment primarily studies the high dimensional entangled systems based on surface plasmon with subwavelength structures. (Opt. Lett. 31, 2792 (2006), Europhys. Lett. 76, 753 (2006).)
Strong influence of periodicity on extraordinary transmission through periodic arrays of subwavelength holes. Quadrate hole array is explored to study the influence of unsymmetrical periodicity on extraordinary optical transmission through periodic arrays of subwavelength holes. It is found that the transmission efficiency of light and the ratio between transmission efficiencies of horizontal and vertical polarized light can be continuously tuned by rotating the quadrate hole array. We can calculate out the transmission spectra (including the heights and locations of peaks) for any rotation angle with a simple theoretical model. (Appl. Phys. Lett. 90, 161112 (2007).)
Interference of surface plasmon polaritions controlled by the phase of incident light. Interference patterns of surface plasmon polaritons(SPPs) are observed in the extraordinary optical transmission through subwavelength holes in optically thick metal plate. It is found that the phase of incident light can be transferred to SPPs. We can control the destructive and constructive interference of SPPs by modulating the relative phase between two incident beams. Using a slightly displaced Mach-Zehnder interferometer, we also gain a picture of interference pattern composed of bright and black stripes. （Submitted）
