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Two-dimensional gap plasmonic waveguide employing surface plasmon polaritons is proposed.Transmission characters of 90 degrees sharp bend waveguide,T-shaped splitter and switch based on gap plasmonic waveguide are numerical simulated with finite-difference time-domain method.It is shown that the energy loss of 90 degrees sharp bend waveguide is ohmic losses which are different to radiation losses of dielectric optical waveguide.When the gap width is larger than 40 nm,the transmission of bend waveguide is larger than straight waveguide with the same length.In the T-shaped splitter,when the gap width ratio of two output waveguides is larger than 0.6,the output energy is mainly assigned to the output waveguide which effective index is smaller.The result is different from dielectric optical splitter.The T-shaped switch is off with two input light out of phase and is on with two input light in phase.The plasmonic modes in the above devices beyond the diffraction limit and can be employed in super-large-scale optical integrated circuit.

Triple-periodical photonic crystal heterostructures (ABC)N for multichannel ultranarrow transmission filters are designed and demonstrated. Theoretical calculations and experimental results from TiO2/SiO2 constructed heterostructures show that each transmission channel can reach subnanometre scale, implying technical importance of such structures in the fields of integrated optics, optical communications for the design of high-performance multichannel filters, wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM) systems, etc.

We theoretically and experimentally demonstrate that refractive index of the prism used to load metal film has significant influence on sensitivity of surface plasmon resonance based sensors. The prism with lower refractive index gives the sensors a higher sensitivity in detecting refractive index variations of a sample. We attribute this effect to the fact that a prism with low refractive index will increase coupling distance between surface plasmons and the medium under investigation.

Utilizing the tool of beam propagation method (BPM) to calculate the zeroth order diffraction beam intensity, we find SVHG displays notched diffraction response as a function of the readout wavelength. Using the method of SA and considering the variance of refractive index as the readout wavelength changes, a practiced notch filter can be designed and the period of the filter is discussed.

Femtosecond pump-probe technique assisted by surface plasmon resonance （SPR） is investigated numerically in this paper. Our calculations show that the signal ratio ΔR/R is increased by 2—3 orders of magnitude higher than the standard pump-probe technique， where ΔR and R are the intensity change and total intensity of the probe beam， respectively. It should also be pointed out that ΔR/R is sensitive to the incident angle of the pump beam and the thickness of the metal film. In particular for the metal-absorbing material system， ΔR induced by the hot electrons in the metal is only 2 percent of that induced by excited absorbing material， so ΔR/R is mainly related to the dynamics of the absorbing material. This technique will be interesting in investigating the ultrafast surface dynamics of thin films.

Numerical simulation has been performed on the optical transmission enhancement of a metallic film with a two-dimensional subwavelength hole array- The results show that the ideal conducting film of the same array structure also presents a transmission enhancement, but the enhancement is not higher than that of the real one- Further analysis reveals that a complicated waveguide coupling effect is responsible for the enhanced transmission- The excitation of surface current on metallic surface transfers the light energy of incidence from metallic surfaces to the holes and then adjusts the optical transmission- We believe that the resonant excitation of surface plasmon is not necessary for the enhancement effect

The red sensitivity of dichromated cellulose triacetate (DCCTA) holographic recording material without any dye sensitization is reported. This sensitivity is due to the absorption of the intermediate chromium (V) formed in the process of Cr６＋→Cr3＋. The real time transmission grating has been recorded using a He-Ne Laser as light source (632.8nm).