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This paper describes a multi-reflected mode based on a narrow waveguide to enlarge the interferential area of surface plasmon polaritons (SPPs). A reasonable thickness of metal film is coated under the waveguide, the incident angle and the waveguide thickness are optimized in order to effectively increase interferential area. This is a key point for research into the Goos–Hanchen shift to optimize the waveguide thickness. Finally, the SPP interferential field is simulated with the finite-difference time-domain (FDTD) technique to prove the optimized results, and indicates that not only is the interferential area enlarged, but the high contrast is also maintained. Furthermore, the mode can fabricate some specific interferential patterns by adding some modulating techniques to the waveguide. So the mode has potential application in the fabrication of sub-wavelength patterns.

A spatial light modulator (SLM) based on surface plasmon polaritons (SPPs) that can generate chromatic pattern is demonstrated. The device is composed of a waveguide with a thin silver film and an active material The simulated results show that the SLM can modulate the intensity of three different wavelengths at the same time and combine a colour picture in the image surface. The SLM also owns the characteristics of high sensitivity, high contrast, fast time response etc. This means that the SLM is promising in the chromatic display.

The use of an attenuated total reflect ion-coup ling mode of prism coated with metal film to excite the interference of the surface plasmon polaritons (SPPs) was proposed for periodic patterning with a resolution of subwavelength scale. High intensity of electric field can be obtained because of the coupling between SPPs and evanescence under a resonance condition, which can reduce exposure time and improve contrast. In this paper, several critical parameters for maskless surface plasmon resonant lithography are described, and the preliminary simulation based on a finite difference time-domain technique agrees well with the theoretical analysis, which demonstrates this scheme and provides the theoretical basis for further experiments.

The thick film photoresist lithography is a much more complicated process compared to the thin film photoresist lithography. In this paper, we have developed a new model for lithography of thick film photoresist by using the angular spectrum theory. The thick film photoresist is divided into many homogeneous layers, and the diffractive optical imaging distribution in photoresist is regarded as superposition of different spectrum plane waves. Propagation of each plane wave is determined by the optical transfer function, and the propagation direction, amplitude and phase are dominated by reflection and transmission between each interface of the sub-layers. The fast Fourier transform (FFT) has been converted into a convolution calculation to keep the computation accurate and reduce computation cost. Numerical calculation results show that optical intensity in cross-sect of thick film resist is strongly affected by reflection, transmission on interface and variation of dielectric permittivity along direction of depth, and therefore these factors should be considered while analyzing diffractive imaging field in thick film photoresist.

We present a narrow band forward scattering optical antenna which is based on the excitation of distinctive whispering gallery modes (WGMs). The antenna is composed of three coaxial cylinder layers: a dielectric layer is sandwiched between a metallic core and cladding. Owing to the destructive interference between the scattering of the outer metallic cladding and the WGM in the backward direction, the power flow in the forward direction is increased. Simulation and analysis show that in proper geometry conditions, the cavity can be tuned into a superscattering state. At this state, both the zeroth and the first order of WGM are excited and contribute to the total scattering. It is shown that the power ratio (power towards backward divided by power towards forward) can be enhanced to about 27 times larger than that for a non-resonant position by the superscattering. Owing to the confinement of the cladding to WGMs, the wavelength range of effective forward scattering is considerably narrow (about 15 nm).

The methods for improving the focusing properties of subwavelength metallic lens by optimizing the groove width and depth of the structure simultaneously are presented. We investigate how the variations of the width and depth of the groove affect the half width at half maximum of the focus, intensity, normal focusing efficiency of the focal spot and the focal length, based on the finite-difference and time-domain method. The optimum design methods of metal lens are put forth through discussing the focusing regularity and physical mechanism, which can provide a theoretical basis for realizing the nano-focusing and flexible manipulation of light wave based on metallic lens.

Interference nanolithography techniques based on long-range surface plasmon polaritons (LR-SPP) are hardly ever achieved by experiments at present. One key reason is that suitable liquid materials are difficult to find as the match layer connects the metal film and the resist. We redesign a Kretschmann−Raether structure for interference lithography. A polymer layer is coated under the metal film, and an air layer is placed between the polymer layer and the resist layer. This design not only avoids the above-mentioned question of the match layer, but also can form a soft contact between the polymer layer and the resist layer and can protect the exposure pattern. Simulation results confirm that a device with an appropriately thick polymer layer can form high intensity and contrast interference fringes with a critical dimension of about λ/7 in the resist. In addition, the fabrication of the device is very easy.

The far-field superlens based on surface plasmon polaritons (SPP) has shown great application potential, but it is difficult and time-consuming to reconstruct the far-field image. We derive a near-field optical transfer function (NOTF) of a silver slab and analyse its validity so that accurate information of nano-scale object in the near-field can be computed rapidly. The NOTF is helpful not only for analysing the super-resolution imaging process in far-field, but also for providing a track to describe the transmission of optical information from near-field to far-field by using the optical transfer functions theory only.