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1.
By using the super-resolution near-field structure (super-RENS) method, the super-resolution recording marks are obtained practically by an organic photochromic diarylethene mask layer, under much lower recording laser power of 0.45roW. The size of recording marks is decreased by 60% (from 1.6μm to 0.7μm) for a diarylethene (photo-mode) recording layer by the optical detection method (limited by optical diffraction), or decreased by 97% (from 160Onto to 5Onto) for a heptaoxyl copper phthalocyanine (thermo-optical) recording layer, the latter is much smaller than the limitation of optical diffraction. In order to obtain a desirable result, a proper extent of photochemistry reaction in the mask layer is needed. Thus, the super-resolution recording marks can be obtained by adjusting the concentration of diarylethene in the mask layer, the recording laser power, and the moving speed of the sample disc. 相似文献
2.
Sb-Bi alloy flms are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb-Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the superresolution pits with diameters of 380 nm are read out by a dynamic setup, the laser wavelength is 780 nm and the numerical aperture of pickup lens is 0.45. The effects of the Sb-Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb-Bi mask layer is about 0.5 m W, and the corresponding carrier-to-noise ratio is about 20 dB at the film thickness of 50nm. The super-resolution mechanism of the Sb-Bi alloy mask layer is discussed based on its temperature dependence of reflection. 相似文献
3.
Received: 20 July 1998/Revised version: 21 September 1998 相似文献
4.
A.M. Kostruba 《Optics & Laser Technology》2009,41(1):5-10
Investigations of optical disc with standard preformatted structure are carried out by null-ellipsometry method. Model of the surface structure of optical disc based on the scalar theory of diffraction is examined. Adequacy of the model suggested to real state of surface for different experimental configurations is estimated. Sensitivity of ellipsometry technique to changes of the optical disc surface structure is determined for two models with different optical parameters of the surface film (n1=1.6; k1=0.02 and n1=1.7; k1=0.3). Minimum changes of microstructure parameters, which can be registered by ellipsometric measurements, are assessed. 相似文献
5.
E.M. de Miguel-Sanz M. Tebaldi S. Granieri N. Bolognini L. Arizmendi 《Applied physics. B, Lasers and optics》2000,70(3):379-383
A photorefractive optical correlator stored and fixed in lithium niobate is presented. The device shows good correlation characteristics
together with very high output efficiency and insensitivity to optical erasure during read-out.
Received: 10 May 1999 / Revised version: 21 June 1999 / Published online: 16 September 1999 相似文献
6.
The polymer poly{1-[2′-methyl-4′-(2″-methylphenylazo) phenylazo]-2-(m-methacryloyloxyoctyloxy}naphthalene, where m = 6, 8, 10, is synthesized by free radical addition polymerization method for holographic optical data storage. Characterization of the polymers is done by formation of the holographic grating. A study of the dependence of diffraction efficiency of the grating formed on various parameters is presented. Surface relief gratings on these polymer films are created upon exposure to argon ion laser beams at 514.5 nm without any subsequent processing steps. The surface structure of the relief gratings has been investigated by atomic force microscopy. The depth of surface relief in a typical case is found to be around 40 nm. 相似文献
7.
C. Grivas D.S. Gill S. Mailis L. Boutsikaris N.A. Vainos 《Applied Physics A: Materials Science & Processing》1998,66(2):201-204
2 O3) thin films on glass substrates is performed by pulsed laser ablation of a metallic indium target in an oxygen atmosphere.
X-ray diffraction analysis verifies that a transition, from amorphous to polycrystalline film growth, occurs at a temperature
of 150 °C. Films grown under optimized conditions exhibit optical transmission higher than 80% in the visible light. Ultraviolet
radiation (λ= 325 nm) induced dynamic holographic recording in films deposited at specific temperature and oxygen pressure
settings is also demonstrated.
Received: 25 April 1997/Accepted: 27 May 1997 相似文献
8.
We propose and develop a new solid immersion lens (SIL), which is called the multilevel phase Fresnel zone plate lens (FZPL) for the near-field (evanescent wave) microscopy. The simple analysis is presented by using the scalar diffraction theory. The outstanding advantages of this FZPL are that it both focuses incident waves and produces evanescent waves. A FZPL can effectively concentrate the high angle rays important for the high resolution in comparison with the conventional SILs. The optical system equipped with the FZPL is not only simple in the assembly but also effective in making an optical head unit. 相似文献
9.
We present a new experimental setup for the optical storage of information via refreshing by inverse seeding (OSIRIS), which
allows a sixfold increase of the storage time of holograms in a Ba0.77Ca0.23TiO3 crystal (BCT). The setup consists of two four-wave mixing processes with common amplified signal waves and phase-conjugated
(pc) waves. Temporal behaviours of the amplified and pc signal waves for the OSIRIS experiment as well as for the common four-wave
mixing experiment are compared and discussed. The solutions of coupled equations under the depleted-pump approximation are
obtained in order to estimate the pc reflectivities and coupling gains of gratings inside the crystal.
Received: 13 December 2000 / Revised version: 26 January 2001 / Published online: 27 April 2001 相似文献
10.
The processing of weak optical signals in spatial-spectral holographic (SSH) materials coherently inverted with optical frequency chirped pulses were investigated. Simulations and experimental studies in Tm3+:YAG were conducted to characterize the parameters of the frequency chirped laser pulse used to invert the SSH material in order to obtain high photon echo efficiency for SSH lidar processing. Collinear and angled beam geometries and single shot and accumulated processes were investigated. Echo efficiencies as high as 450% were measured, significantly higher than the typical stimulated photon echo efficiency of 10%. 相似文献
11.
Mode splitting was observed when a He-Ne laser beam was reflected through a prism-coupled liquid-crystal slab waveguide under
an applied electric field. The splitting manifests itself as the imposed voltage reaches a critical level, and diminishes
when the voltage increases above a critical high value. If the applied voltage increases even further, mode splitting vanishes,
attributing to the result that almost all the directors of the liquid crystal turn upright to the surface. The multi-layer
matrix simulation can satisfactorily account for this phenomenon by exploiting the property of the anisotropic optical birefringence
of a liquid crystal under applied voltages.
Received: 2 December 2002 / Revised version: 24 January 2003 / Published online: 23 May 2003
RID="*"
ID="*"Corresponding author. Fax: +886/3572-3052, E-mail: jtlue@phys.nthu.edu.tw 相似文献
12.
A long-lasting development in the area of holographic recording materials has shown that gelatin, a natural material, can
be used as a medium for the holographic recording. Dichromated gelatin is a result of the effort to obtain phase holographic
optical elements with high diffraction efficiency. This paper gives overview of its importance for holography, difficulties
with its treatment, possibilities of its utilization, optical properties, and explains chemical processes being under way
in gelatin from its exposure to fixing. Our experience with the formation of holographic optical elements into dichromated
gelatin is mentioned.
This work was supported by the project LN00A015 of the Ministry of Education of the Czech Republic. 相似文献
13.
N. Starbov T. Missana C. N. Afonso K. Starbova M. A. Ollacarizqueta 《Applied Physics A: Materials Science & Processing》1996,63(2):161-165
Bilayer Sb/Se films are irradiated with 12 ns pulses from an ArF laser (extended areas) and from a focused Ar+ laser (micron-sized areas). Real-time reflectivity measurements are used to determine if the process occurs within the solid or liquid phase and the transformation time, in addition to measure the optical contrast and the medium sensitivity. Transmission electron microscopy is used to analyze the structure of the transformed areas and the medium resolution. The results show that mixing is initiated by preferential melting at the grain boundaries and an amorphous phase is produced upon irradiation at high energy densities. Finally, the characteristics of the mixing process in Sb/Se films as a write-once optical recording mechanism are discussed in terms of the sensitivity and resolution of the recorded spots and the time required for recording. 相似文献
14.
Study of the ambient optical recording dynamics on sputtered indium oxide thin films 总被引:1,自引:0,他引:1
K. Moschovis E. Gagaoudakis E. Chatzitheodoridis G. Kiriakidis S. Mailis E. Tzamali N.A. Vainos H. Fritzsche 《Applied Physics A: Materials Science & Processing》1998,66(6):651-654
2 O3) thin films, grown by dc magnetron sputtering, using ultraviolet laser radiation at 325 nm, is investigated. Simultaneous
measurements of the recording efficiency and electrical conductivity changes, under ambient conditions, prove that there is
a strong relation between the two actions, and measurements of the recording efficiency with respect to the film conductivity
history and temperature provide evidence for the presence of two coexisting processes in the recording regime. The reported
results provide essential information on the mechanism and nature of holographic recording in this material.
Received: 4 November 1997/Accepted: 16 November 1997 相似文献
15.
A. Murciano S. Blaya L. Carretero M. Ulibarrena A. Fimia 《Applied physics. B, Lasers and optics》2005,81(2-3):167-169
In this paper, we present a photopolymerizable material in a sol-gel matrix suitable for recording a large number of multiplexed diffraction gratings with low total exposure energy. The matrix of this material is an inorganic porous silica glass, a material that does not shrink when radical photopolymerization is initiated. The photosensitive component is based on acrylamide, N,N′-methylenebisacrylamide, triethanolamine and yellow eosine as a photoinitiator. In the reported study, 50 holograms were angularly multiplexed with diffraction efficiencies between 0.1 and 1.9% resulting in a dynamic range of M/# = 3.9. The total exposure was 4.5 mJ/cm2 and the energy used in recording each hologram was 95 μJ/cm2. This indicates a very high sensitivity for this material in the range of 3.3 to 15.5 cm/mJ. Due to this good holographic performance, the material is suitable for holographic data storage applications. 相似文献
16.
We describe theoretically the function of a nonlinear optical element based on photoanisotropy in azo-dye-doped polymers for
optical correlation. This element allows the realization of a matched filter with two incoherent light beams. The described
technique involves the insertion of a photoanisotropic polymer sample in the Fourier plane of the optical element. Due to
the specific features of photoanisotropic materials the output is characterized by the convolution of the first wave with
the autocorrelation function of the second wave.
Received: 29 March 1999 / Revised version: 14 June 1999 / Published online: 16 September 1999 相似文献
17.
New photopolymerizable holographic recording material based on polyvinylalcohol and 2-hydroxiethylmethacrylate (HEMA) 总被引:2,自引:0,他引:2
S. Blaya L. Carretero R.F. Madrigal M. Ulibarrena A. Fimia 《Applied physics. B, Lasers and optics》2002,74(6):603-605
We have developed a new polyvinylalcohol-based photopolymeric holographic recording material. The recording is obtained by
the copolymerization of acrylamide and 2-hydroxiethylmethacrylate (HEMA). Diffraction efficiencies near 70% are obtained with
exposures of ≈65 mJ/cm2 in materials of 110-μm thickness. The addition of HEMA increases the thickness of the film, which results in improved storage
capacity for holographic optical storage.
Received: 7 March 2002 / Published online: 2 May 2002 相似文献
18.
The photoinduced birefringence in an azobenzene polymer is investigated at different temperatures between -20℃ to 50℃. It is found that there is a peak value of photoinduced birefringence in the temperature dependence of the photoinduced birefringence under a certain pumping intensity. With the pump light in 90mW/cm^2, the peak value of the photoinduced birefringence appeared at about 0℃ C. The effect of temperature on the photoinduced birefringence is discussed using the competition mechanism between the photoinduced reorientation and the thermal random motion. 相似文献
19.
J.?Villarroel M.?Carrascosa A.?García-Caba?es O.?Caballero-Calero M.?Crespillo J.?Olivares 《Applied physics. B, Lasers and optics》2009,95(3):429-433
The photorefractive behaviour of a novel type of optical waveguides fabricated in LiNbO3 by swift heavy ion irradiation is investigated. First, the electro-optic coefficient r
33 of these guides that is crucial in the photorefractive effect is measured. Second, two complementary aspects of the photorefractive
response are studied: (i) recording and light-induced and dark erasure of holographic gratings; (ii) optical beam degradation
in single-beam configuration. The main photorefractive parameters, recording and erasing time constants, maximum refractive-index
change and optical damage thresholds are determined. 相似文献
20.
Rachid Hamdi Badr-Eddine Benkelfat Qin Zou Yaneck Gottesman 《Optics Communications》2007,269(1):64-68
We demonstrate that in addition to their role in tuning the wavelength of an N-stage hybrid liquid-crystal Šolc filter, liquid-crystal cells can also be used to vary the transmission bandwidth of such filter around any of the tuned wavelength. This bandwidth tuning is based on the variation of the number of stages by what we call here an “optical cancelling technique”. This is achieved by varying the birefringence of the liquid-crystal cells whose optical path difference switches between two particular values. We show that for a 10-stage filter and at λi = 1.532 μm, the calculated 3-dB bandwidth varies from 2.6 to 11.8 nm when the number of “optically-cancelled” hybrid plates increases from 0 to 8. During the tuning process, the contrast ratio remains equal to that of the equivalent classical Šolc filter. 相似文献