Surface Plasmon polaritons are electromagnetic waves that propagate along the surface of a conductor, usually a metal. It
is shown that the gain-assisted metamaterial can compensate for the intrinsic absorption loss in metal. In this paper, the
propagation of surface plasmon polaritons on gain-assist metamaterial system is investigated. As an example,
nanolithography has been considered by using optical proximity exposure in the evanescent near field of gain-assisted
metamaterial layer. The evanescent waves carried the detailed information of the object which was defined by the high
space frequency of the mask. With the enhancement of surface plasmon polaritons and gain-assisted metamaterials
system, the evanescent waves can be propagated to a relatively far distance. Numerical computations by finite element
analysis shows that better optimization of the gain-assisted metamaterials system can further improve the resolution.
Experiments will be developed to prove the simulation by using a modified i-line aligner. The computation result shows
it will be an alternative nanolithography technique for the next generation lithography.
Photon sieve is a novel diffractive optical element modulating either amplitude or phase which consists of a great
number of pinholes distributed appropriately over the Fresnel zones for the focusing and imaging of light. Photon sieve
has the advantages of the diameter of pinholes beyond the limitation of the corresponding Fresnel zone width and the
minimum background in the focal plane. Furthermore, photon sieve can be fabricated on a single surface without any
supporting struts required unlike the Fresnel zone plate. Photon sieve can be used as EUV telescope for solar orbiter,
space-based surveillance telescope operating at visible light, or other imaging components. Photon sieve can also be
used as one of the promising lithographic tools for nanoscale science and engineering to obtain the lower cost, higher
flexibility and better resolution. The approaches to enhancing imaging resolution of photon sieve are presented in detail.
According to Fresnel-Kirchhoff diffraction theory, the diffractive field of photon sieve is described by means of the
discrete fast Fourier transform algorithm. The related contents include the calculation of point spread function, the
suppression of side lobes, the imaging bandwidth, the physical limit of resolution, and the diffraction efficiency. Imaging
properties of photon sieve are analyzed on the basis of precise test.
Contrast enhancement is important for small target detection and tracking. Conventional contrast enhancement
techniques often fail to produce satisfactory results for images expressing unimodal intensity histograms. This paper
presents a new contrast enhancement method based on rough set theory which is especially suitable for such images. The
method uses the max of between-class mean to partition the image into two sub-images, the denoised target region and
the denoised background region. Then the target region is enhanced by extend histogram. Experimental results indicate
the new enhancement method is more suitable than traditional methods for handling the enhancement problems of low
contrast small target images.
A new detection algorithm of dim moving targets in the IR image sequences is presented. The images consist mainly of
sensor noise, drifting background clutter and low contrast targets. So it is difficult to provide reliable detection in just a
single frame. This algorithm adopts multi-scale gradient to suppress the clutter according to its spatial distribution
feature. Then the recursive maximum similarity (RMS) filter is used to accumulate targets energy in temporal domain.
The advantage of the algorithm is that it realizes the enhancement of the target gradient feature and clutter suppressing in
the same time. The results show that the algorithm can effectively detect the real small dim targets even if there is strong
Nanolithography has been investigated by using optical proximity exposure in the evanescent near field in nano-filmed
noble metals. Sub-diffraction-limited feature size can be resolved by using i-line illumination exposure. Compared with
the model of original superlens, we separated the superlens 100nm away from the mask, under the illumination of i-line
light, the initial simulation shows that the sub-diffraction-limited feature as small as 60nm linewidth with 120nm pitch
can be clearly resolved without hard contact between mask and nano-filmed noble metal. By proper design of the
materials and the parameters of nano-filmed layers, better resolution can be realized.
Photon sieve is a kind of diffractive optical element modulating either amplitude or phase and thus suffers from
chromatic aberration or low diffraction efficiency. The narrowband imaging properties of photon sieve are illustrated
with point spread function test and resolution target test. Hybrid lens consisting of both refractive optical surfaces and
photon sieve are suggested to correct the chromatic aberration. Phase-photon sieve technology and surface plasmon polaritons technology may be promising approaches to improve the diffraction efficiency.
We present the lithography scheme that use high-numerical-aperture photon sieves array as focusing elements in a
scanning X-ray maskless nanolithography system. The system operating at wavelength of 0.5~2nm synchrotron light
sources radiated, each of a large array of photon sieves focuses incident X-ray into a diffraction-limited on-axis
nanoscale spot on the substrate coated photoresist. The X-ray intensity of each spot is modulated by means of a spatial
light modulator. Patterns of arbitrary geometry are exposed and written in a dot matrix fashion while the substrate on a
stepping stage is precisely driven in two dimensions according to the computer program. The characteristics of
synchrotron radiation light, resolution limits and depth of focus of the lithographic system are discussed. The design and
fabrication of photon sieve are illustrated with a low-numerical-aperture amplitude-photon sieve fabricated on a chrome-coated
quarts plate by means of laser-beam lithographic process, which minimum size of pinhole was 5.6um. The
focusing performance of the photon sieve operating at wavelength of 632.8nm was simulated and tested.
This paper presents a new automatic image segmentation method for segmenting moving object in complex environment by combining the motion information with edge information. We propose an adaptive optical flow method based on the Horn-Schunck algorithm to estimate the optical flow field. Our method puts different smoothness constraints on different directions and optical flow constraint is used according to the gradient magnitude. Canny edge detector can obtain the most edge information but miss some pixels. In order to restore these missing pixels the edge has a growing based on the continuity of optical flow field. Next, by remaining the block that has the longest edge could delete the noise in the background, and then the last segmentation result is obtained. The experimental result demonstrates that this method can segment the moving object in complex environment precisely.