Surface plasmon polariton,a kind of surface electromagnetic wave propagating along the interface between metals and dielectrics,provides an excellent platform for the realization of integrated photonic devices due to its unique properties of confining light into subwavelength scales.Our recent research progresses of nanoscale integrated photonic devices based on surface plasmon polaritons,including all-optical switches,all-optical logic discriminator,and all-optical routers,are introduced in detail.
Quantum manipulation of macroscopic mechanical systems is of great interest in both fundamental physics and ap- plications ranging from high-precision metrology to quantum information processing. For these purposes, a crucial step is to cool the mechanical system to its quantum ground state. In this review, we focus on the cavity optomechanical cooling, which exploits the cavity enhanced interaction between optical field and mechanical motion to reduce the thermal noise. Recent remarkable theoretical and experimental efforts in this field have taken a major step forward in preparing the mo- tional quantum ground state of mesoscopic mechanical systems. This review first describes the quantum theory of cavity optomechanical cooling, including quantum noise approach and covariance approach; then, the up-to-date experimental progresses are introduced. Finally, new cooling approaches are discussed along the directions of cooling in the strong coupling regime and cooling beyond the resolved sideband limit.
This paper summarizes our research work on optoelectronic devices with nanostructures. It was indi- cated that by manipulating so called ＂general energybands＂ of fundamental particles or quasi-particles, such as photon, phonon, and surface plasmon polariton （SPP）, novel optoelectronic characteristics can be obtained, which results in a series of new functional devices. A silicon based optical switch with an extremely broadband of 24 nm and an ultra-compact （8 μm -17.6μm） footprint was demonstrated with a photonic crystal slow light waveguides. By proposing a nanobeam based hereto optomechanical crystal, a high phonon frequency of 5.66 GHz was realized experimentally. Also, we observed and verified a novel effect of two-surface-plasmon-absorption （TSPA）, and realized diffraction-limit-overcoming photolithography with resolution of-1/11 of the exposure wavelength.
The miniaturization of polarization beam splitters(PBSs) is vital for ultradense chip-scale photonic integrated circuits. However, the small PBSs based on complex hybrid plasmonic structures exhibit large fabrication difficulties or high insertion losses. Here, by designing a bending multimode plasmonic waveguide, an ultrabroadband on-chip plasmonic PBS with low insertion losses is numerically and experimentally realized. The multimode plasmonic waveguide, consisting of a metal strip with a V-shaped groove on the metal surface, supports the symmetric and antisymmetric surface plasmon polariton(SPP) waveguide modes in nature. Due to the different field confinements of the two SPP waveguide modes, which result in different bending losses, the two incident SPP waveguide modes of orthogonal polarization states are efficiently split in the bending multimode plasmonic waveguide. The numerical simulations show that the operation bandwidth of the proposed PBS is as large as 430 nm because there is no resonance or interference effect in the splitting process. Compared with the complex hybrid plasmonic structure, the simple bending multimode plasmonic waveguide is much easier to fabricate. In the experiment, a broadband(Δλ≈ 120 nm) and low-insertion-loss(<3 dB with a minimum insertion loss of 0.7 dB) PBS is demonstrated by using the strongly confined waveguide modes as the incident sources in the bending multimode plasmonic waveguide.
