共查询到20条相似文献,搜索用时 15 毫秒
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A novel super-resolution near-field optical structure (super-RENS) with bismuth (Bi) mask layer is proposed in this paper. Static optical recording tests with and without super-RENS are carried out using a 650-nm semiconductor laser at recording powers of 14 and 7 mW with pulse duration of 100 ns. The recording marks are observed by high-resolution optical microscopy with a charge-coupled device (CCD)camera. The results show that the Bi mask layer can also concentrate energy into the center of a laser beam at low laser power similar to the traditional Sb mask layer. The results above are further confirmed by another Ar+ laser system. The third-order nonlinear response induced by the plasma oscillation at the Bi/SiN interface during laser irradiation can be used to explain the phenomenon. The calculation results are basically consistent with our experimental results. 相似文献
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In this study, super-RENS disc read-out signals were modeled with various nonlinear models. In the results of modeling the nonlinearity, DC offset, and domain bloom phenomena of the super-RENS channel with a second-order Volterra filter, it was identified that the number of significant quadratic coefficients was relatively small. Therefore, a sparse Volterra model and a truncated Volterra model are applied to effectively model the nonlinear channel. In addition, the Hammerstein-type asymmetric conversion model is employed to model the nonlinear channel for the purpose of comparison. The results demonstrate that the sparse model of a simplified polynomial form achieves good modeling performance for the super-RENS disc read-out signals. 相似文献
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Below-diffraction-limited hybrid recording using silicon thin film super-resolution structure 下载免费PDF全文
We report on new experimental results for
below-diffraction-limited hybrid recording. In our experiments, by
means of focused laser assisted magnetic recording, the magnetic
domains within TbFeCo thin films are obtained under an external
perpendicular direct magnetic field. For a single magnetic medium,
the domain size is mainly determined by the focused spot, which is
about 620~nm for the laser wavelength λ =406~nm, and
a numerical aperture of the lens of 0.80. However, when a silicon thin
film structure is inserted between the substrate and the magnetic medium,
the recording domains can be reduced obviously. By optimizing the
experimental condition, even the size can be reduced to about
100~nm, which is below the diffraction limit, i.e. about 1/6 of the spot
size. This is very useful for improving the hybrid recording density
in practical applications. 相似文献
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Daiichi Koide Takeshi Kajiyama Ryuji Sato Haruki Tokumaru Yoshimichi Takano 《Optical Review》2014,21(5):541-544
We report on the recording characteristics of a near-field optical recording thin optical disk (NFR-TOD). We proposed a new cooling-less-type write strategy for recording, applied it to the NFR-TOD experimental system, and also applied a partial response maximum likelihood (PRML) signal processing, which was evaluated and optimized the PR coefficient for playback signals of the prototype NFR-TOD. The NFR-TOD has a track pitch of 160 nm and improved recording characteristics. The experimental results of the prototype NFR-TOD and the system indicate sufficiently low bit error rates (bERs) for recorded data at a fourfold higher recording density than the current Blu-ray disk. 相似文献
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The transmittive and reflective Z-scan technique is used with a 10 Hz, frequency doubled, Q-switched, and mode-locked Nd:YAG laser to verify that the reflectivity of the super-resolution near-field structure of an SiN/Sb/SiN thin film increases as incident intensity decreases. This intensity-dependent reflection, called nonlinear reflection, reflects a TEM(00) mode laser beam more strongly at its periphery than at its center and so shrinks the transmitted laser beam. The observed nonlinear reflection is attributed to laser-induced change of carrier densities in Sb, to justify quantitatively the experimental results. 相似文献
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The plasmon and distribution effects of collective localized surface plasmons between incident light and active layer of PtOx-type super resolution near-field structure (super-RENS) have been studied using finite-difference time-domain method. Four types of distribution of Pt nanoparticles, i.e., type A, B, C, and D in active layer are investigated. We find that type C and D in active layer can provide higher field intensity in a wider range of particle size when the particle sizes are varied, and the out-going filed emerging from the active layer exhibit smaller spot size than those of type A and B. Type B, C and D also provide the additional path longer than that of type A, and excite more evanescent field which located in the far edge of the bubble from the optical axis of the incident beam. Results show that the type C structure is the best choice in the view point of designing the PtOx-type super-RENS. This study provides new information to design a super-RENS with superior resolution as well as other applications in nano photonic devices. 相似文献
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Optical Review - Heat-assisted magnetic recording (HAMR) is a promising technology for achieving more than 10 Tbit/inch2 recording density. A near-field transducer (NFT), which forms a small light... 相似文献
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Y.-F. Chau Y.-S. Sun D.P. Tsai T.-J. Yang 《Applied Physics A: Materials Science & Processing》2007,89(2):381-385
The deformation and plasmon effects of collective localized surface plasmons between incident light and bubble-pit AgOx-type super-RENS structure have been studied using finite-difference time-domain (FDTD) method. We find that the polarization,
wavelength of incident light, and particle sizes of Ag nanoparticles are sensitive to the plasma resonance. The Ag nanoparticles
inside the bubble-pit AgOx-type super-RENS structure give the additional outer boundaries to the motion of the Ag nanoparticles, and excite more evanescent
field which located in the far edge of the bubble from the optical axis of the incident beam. The optical properties between
active layer and incident light with polarization direction, different wavelengths, and varied particle sizes of Ag nanoparticles
exhibits nonlinear optical behavior in the near field. The far-field signals of different wavelength of incident light confirm
the relation between highly localized near-field distributions and enhanced resolution of far-field signals. The subwavelength
recording marks smaller than the diffraction limit were distinguishable since the Ag nanoparticles with high localized fields
transferred evanescent waves to detectable signals in the far field.
PACS 42.79.Vb; 71.15.Rn; 72.15.Rn; 73.22.-f; 73.22.Lp; 78.67.Bf; 73.20.Mf 相似文献
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A new phase-correction method in a realistic loss superlens imaging system is theoretically predicted.The image resolution is enhanced using the near-field active phase-correction method.Resolvable separation between two slits has been significantly improved toλ/20 for the symmetrical superlens system andλ/12 for unsymmetrical system. 相似文献
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The occurrence of self-excited pressure oscillations routinely plagues the development of combustion systems. These oscillations are often driven by interactions between the flame and acoustic perturbations. This study was performed to characterize the structure of the acoustic field in the near field of the flame and the manner in which it is influenced by oscillation frequency, combustor geometry, flame length and temperature ratio. The results of these calculations indicate that the acoustic velocity has primarily one- and two-dimensional features near the flame tip and base, respectively. The magnitude of the radial velocity components increases with temperature ratio across the flame, while their axial extent increases with frequency. However, the acoustic pressure has primarily one-dimensional characteristics. They also show that the acoustic field structure exhibits only moderate dependencies upon area expansion and flame temperature ratio for values typical of practical systems. Finally, they show that the local characteristics of the acoustic field, as well as the overall plane-wave reflection coefficient, exhibit a decreasing dependence upon the flame length as the area expansion ratio increases. 相似文献
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《Current Applied Physics》2008,8(5):577-582
Near-field recording (NFR) technology using a flying optical head is applied for high density optical data storage. Diamond-like carbon (DLC) film and PFPE lubricant film are coated on utmost NFR disk to reduce the tribological problems. A contamination at the head–disk interface (HDI), especially on a solid immersion lens (SIL) is observed. The contaminants are composed of dust materials from the surroundings and lubricant materials from a disk surface. The contaminants are supposed to be condensed by heat from a writing laser beam at the HDI. To avoid the contamination problem, a cover-layer is coated and a focal plane moved under the cover-layer from the HDI. First-surface near-field recording configuration can be modified by laminating a cover-layer, which enhances the possibility of a practical application with a media removability function. 相似文献
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This investigation deals with the range in operating currents for which a Josephson interferometer, sometimes also referred
to as Superconducting QUantum Interference Device (SQUID), may remain in the zero-voltage Josephson condition. An interferometer
consists of one or more inductive loops each of which contains two Josephson junctions or other weak links. Two types of current
are considered. Gate currentI
gpasses the junctions in parallel. Control currentI
cgenerates magnetic flux via inductive coupling in the loops. Zero-voltage operation is possible within certain areas of theI
g,I
cplane. These areas are manifestations of flux-quantum states and their boundary lines are referred to as static characteristics.
In view of the nonlinearity of the constituting equations, not all their formal solutions are physically realizable. A stability
analysis yields criteria which permit the identification of realizable operating conditions. The static characteristics comprise
operating conditions where the limit of stability is reached. To obtain the static characteristics, linearized equations may
be utilized if theLI
o product, a measure for the size of an interferometer, is large compared to the flux quantumΦ
0, whereL is the inductance per loop, andI
o the maximum Josephson current per junction. As a general method of solving system of transcendental equations, continuation
is discussed. The utilization of continuation for obtaining interferometer characteristics is explained. It is shown that
some changes in the gate-current feed arrangement are equivalent to shearing the characteristics in theI
g,I
cplane. Analytical results are given on extrema, inflexion points, and singularities in the shape of cusps which conceptually
relate to the existence and connectivity of flux-quantum states. Experimental static characteristics are presented on two-and
four-junction interferometers. They are in agreement with characteristics computed on the basis of simple lumped circuit models.
Relevant circuit parameters are obtained from the experimental characteristics. 相似文献