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1.
The second order nonlinear optical properties associated with second harmonic generation and linear electro-optic effect have been computed for l-alanine amino acid single crystals using semi-classical anharmonic oscillator model. The data obtained for l-alanine were compared with the optical parameters of similar amino acid single crystal. The results have been discussed in detail. 相似文献
2.
Widely tunable terahertz (THz)-wave generation using difference frequency generation (DFG) in an organic N-benzyl-2-methyl-4-nitroaniline (BNA) crystal was demonstrated. To our knowledge, this is the first report of THz-wave generation by BNA DFG. Large, high-quality single crystals of BNA (phi 8 mm x 30 mm) were grown using the vertical Bridgman method. The nonlinear optical (NLO) coefficient d(33) of the BNA crystal is approximately 234 pm/V, which is the largest value reported for any yellow NLO material. The collinear phase-matching condition of the type-0 configuration is satisfied using a 0.7-1 microm band pump wavelength. We generated THz waves using an organic BNA crystal; the generation range is 0.1-15 THz. 相似文献
3.
Hongliang Yang Quan Ren Guanghui Zhang Yuk Tak Chow Hau Ping Chan Pak Lim Chu 《Optics & Laser Technology》2005,37(4):143-264
Bismuth titanate, Bi4Ti3O12 (BTO), is a typical ferroelectric material with useful properties for optical memory, piezoelectric and electro-optic devices. Its nano-crystals were compounded by the chemical solution decomposition technique. Its structure and size were analyzed by X-ray diffraction and transmissive electron microscopy. The composite thin film of BTO nano-crystals and high transparency polymethylmethacrylate (PMMA) polymer was prepared by spin coating. The transmitted spectrum of BTO/PMMA composite thin film in 300–1500 nm was measured. The film thickness d and the optical constants of the film, such as the refractive index n, the absorption coefficient α, and the extinction coefficient κ were obtained using the data from the transmitted spectrum. 相似文献
4.
A tunable Fabry-Perot (F-P) filter by using electro-optic polymer film is proposed. The electro-optic polymer is alkoxysilane dye (ASD)/SiO2-TiO2 hybrid material, whose electro-optic coefficient γ33 is about 5 pm/V. The wavelength tuning range of 3.8 nm under 400-V DC voltage and the nonlinear characteristic with the electric field have been obtained via electro-optical properties of polymer. Both of polymer film fabrication and F-P filter design have been introduced. The tunable F-P filter is designed for the application of two-input/two-output port wavelength-selective optical switch. Also, some problems have been discussed in this letter. 相似文献
5.
Şadan Korkmaz Saliha Elmas Naci Ekem Suat Pat M. Zafer Balbağ 《Optics Communications》2012,285(9):2373-2376
In this study, optical and surface properties of MgF2 thin films produced by thermionic vacuum arc (TVA) technique have been investigated. By means of this technique the MgF2 thin film produced by condensing the plasma of anode material generated by using TVA under high vacuum conditions on the glass. The optical properties have been investigated by using Filmetrics F20 and UV/VIS spectrometer. For surface properties of produced thin films EDS, SEM and AFM have been used. Our analysis shows that MgF2 thin films produced by using TVA are proper single and multi layer anti-reflective (AR) coating and TVA technique brings very important advantages for ophthalmic glass coating and industrial applications' optical purposes. 相似文献
6.
Wei Shi Xin Yin Changshui Fang Qiwei Pan Qingtian Gu Xiangwen Wu Dong Xu Hongzhen Wei Jinzhong Yu 《Optics and Lasers in Engineering》2001,35(2):121
The polyetherketone (PEK-c) guest–host polymer thin films doped with disperse red 13 were prepared by spin-coating method. The corona poling condition was optimized by the poling profiles. The polymer films were poled by corona-onset poling at elevated temperature, and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. The linear electro-optic coefficients of the poled polymer films have been determined at λ=632.8 nm by using a new simple interferometric technique, which is based on compensating the change of the optical length due to the electro-optic effect of the poled polymer film by the anti-piezoelectric effect of a quartz crystal. 相似文献
7.
DONG Xuying GAN Fuxi GU Donghong YIN Jinlong 《Chinese Journal of Lasers》2000,9(4):349-355
1 Introduction High densityinformationstorageisanimportanttechnologicalobjective.Toincreasetherecordingdensityisoneoftheimportantsubjectsinthecurrentandfuturedevelopmentofopticalstoragetechnology .Thedigitalversatiledisc recordable (DVD R)formathasbeenpr… 相似文献
8.
M. Abarkan M. Aillerie J. P. Salvestrini M. D. Fontana E. P. Kokanyan 《Applied physics. B, Lasers and optics》2008,92(4):603-608
We report the optical and dielectric properties in hafnium (Hf)-doped lithium niobate (LN) crystals. We investigated samples
of congruent composition with various doping concentration varying from 0 to 8 mol%. The clamped and unclamped values of the
electro-optic coefficient r
22 of Hf-doped LN and the corresponding dielectric permittivity as well, have been experimentally determined and compared with
the results obtained in undoped congruent LN crystals. We show that the electro-optic and dielectric properties are only slightly
affected by the introduction of hafnium ions, and therefore Hf-doped LN has the advantage of low photorefractive damage compared
with the undoped congruent LN. 相似文献
9.
Molybdenum ditelluride, MoTe2, thin films have been prepared on a glass substrate by depositing first a layer of Mo of 1 μm thickness by rf sputtering and then layers of tellurium of 4 μm thickness followed by annealing, in a vacuum sealed Pyrex tube, at 823 K for one hour. The films have been studied by X-ray diffraction, electron microprobe analysis, scanning electron microscopy and for optical and electrical properties. This indicated that the films so prepared are well crystallized and textured with a hexagonal structure similar to 2H-MoS2. However, the film is non stoichiometric due to the presence of small amounts of oxygen. The optical properties are in good agreement with those of single crystals and film deposited by other means. The room temperature conductivity is of the same order of magnitude as that of single crystals. Finally, MoTe2 has been used as a precursor for the growth of MoTe2−xSx films. 相似文献
10.
W.-C. Liu A.-D. Li J. Tan D. Wu H. Ye N.-B. Ming 《Applied Physics A: Materials Science & Processing》2005,81(3):543-547
Pb(Zr0.52Ti0.48)O3 (PZT) nanocrystals and transparent polycarbonate (PC) composite thin films with useful properties for ferroelectric, piezoelectric and electro-optic devices were prepared by a spin-coating technique. Ultra-fine PZT (∼40–50 nm) nanocrystals with pure perovskite tetragonal phase were synthesized by a hydrothermal method. The structure and morphology of the composite thin films were studied by means of X-ray diffraction and scanning electron microscopy. To obtain the optimum electro-optic properties of poled composite films, the poling condition under an external electric field was optimized through the dielectric properties of PZT and PC polymer and effective field intensity theory. The electro-optic coefficient of the poled PZT/PC composite film is estimated to be 30.5 pm/V. The transparency spectra were measured and the optical band gaps of the unpoled, poled at 145 °C and poled at 165 °C composite thin films are estimated to be 4.26 eV, 4.21 eV and 4.18 eV, respectively. The measured dielectric constants of PZT/PC are in good agreement with the calculated values for the composite with a very small PZT volume fraction, based on the Onsager effective-field theory. This offers a reliable and indirect way to predict the dielectric constant of nanocrystals. PACS 81.40.Tv; 78.66.Sq; 78.66.Vs 相似文献
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13.
The electro-optic (E-O) properties of the slab polymer waveguide induced by electric poling have been studied experimentally. The thin film waveguide was prepared by a synthesized polymer polypelargonamide and poled by applying voltage between the electrodes. I–V curves and E-O characteristics of the polymer films were in-situ measured during poling. In order to evaluate the molecular dipole orientation under the poling field, the absorption spectra of this film was observed by FTIR. The E-O performance of the polymer slab film was also estimated by the Mach–Zehnder interferometer. 相似文献
14.
S.M. Kostritskii P. Bourson M. Aillerie M.D. Fontana D. Kip 《Applied physics. B, Lasers and optics》2006,82(3):423-430
Nominally pure lithium tantalate (LiTaO3) crystals with different chemical compositions were characterized by Raman scattering, infrared reflection, and infrared
absorption spectroscopy. In these crystals specific phonon bands are correlated to electro-optic and nonlinear optical properties.
The electro-optic and nonlinear optical coefficients were determined and the data are compared with literature values obtained
by direct measurements. Our measurements are in good accordance with the literature data, which opens up a new possibility
for fast and easy estimation of electro-optic and nonlinear optical performance of newly developed LiTaO3-based materials modified by stoichiometry.
PACS 42.70.Mp; 78.20.Jq; 78.30.-j 相似文献
15.
<正>This paper reports that GaSb thin films have been co-deposited on soda-lime glass substrates.The GaSb thin film structural properties are characterized by Raman spectroscopy.The Sb-A1g/GaSb-TO ratio decreases rapidly with the increase of substrate temperature,which suggests a small amount of crystalline Sb in the GaSb thin film and suggests that Sb atoms in the thin film decrease.In Raman spectra,the transverse optical(TO) mode intensity is stronger than that of the longitudinal optical(LO) mode,which indicates that all the samples are disordered.The LO/TO intensity ratio increases with increasing substrate temperature which suggests the improved polycrystalline quality of the GaSb thin film.A downshift of the TO and LO frequencies of the polycrystalline GaSb thin film to single crystalline bulk GaSb Raman spectra is also observed.The uniaxial stress in GaSb thin film is calculated and the value is around 1.0 GPa.The uniaxial stress decreases with increasing substrate temperature.These results suggest that a higher substrate temperature is beneficial in relaxing the stress in GaSb thin film. 相似文献
16.
Optical properties of hexagonal boron nitride thin films deposited by radio frequency bias magnetron sputtering 下载免费PDF全文
The optical properties of hexagonal boron nitride (h-BN) thin films
were studied in this paper. The films were characterized by Fourier
transform infrared spectroscopy, UV--visible transmittance and
reflection spectra. h-BN thin films with a wide optical band gap Eg (5.86 eV for the as-deposited film and 5.97 eV for the
annealed film) approaching h-BN single crystal were successfully
prepared by radio frequency (RF) bias magnetron sputtering and
post-deposition annealing at 970~K. The optical absorption behaviour
of h-BN films accords with the typical optical absorption
characteristics of amorphous materials when fitting is made by the
Urbach tail model. The annealed film shows satisfactory structure
stability. However, high temperature still has a significant
effect on the optical absorption properties, refractive index n,
and optical conductivity σ of h-BN thin films. The
blue-shift of the optical absorption edge and the increase of Eg probably result from stress relaxation in the film under high temperatures. In addition, it is found that the refractive index
clearly exhibits different trends in the visible and ultraviolet regions.
Previous calculational results of optical conductivity of h-BN
films are confirmed in our experimental results. 相似文献
17.
Hybrid photonic crystals consisting of a thin-film opal and a thin profiled gold film situated on the surface or inside the
opal have been prepared. The optical transmittance spectra of hybrid crystals have been studied. It has been found that the
spectra exhibit minima due to diffraction resonances in the photonic crystal and bands of enhanced transmission due to transfer
of radiation through the metal film surface by plasmon polaritons. It has been shown that the transmittance spectra of hybrid
crystals with a metal film on the surface are subjected to a stronger modification than the hybrids having a metal film inside
the crystal. 相似文献
18.
Based on the phenomenological Landau-Devonshire theory, we investigate the film thickness dependence of ferroelectric and electro-optic properties of epitaxial BaTiO3 thin films grown on SrTiO3 and MgO substrates. By using the effective substrate lattice parameter concept, the film thickness dependence of misfit strain is incorporated into the theory. Therefore, the film thickness dependence of ferroelectric and electro-optic properties in epitaxial BaTiO3 thin films can be explained. Moreover, a large quadratic electro-optic effect was obtained in the BaTiO3 thin films, which is in good agreement with the experimental result of BaTiO3 thin films on the MgO substrate. 相似文献
19.
Preparation and analysis of thin films containing samarium sulfide (SmS) is presented along with a review of relevant SmS properties. Films were deposited onto unheated substrates by the reactive evaporation of samarium in a backpressure of hydrogen sulfide. This technique yields films that contain significant quantities of impurities; however high-quality SmS crystals are also formed. A phase transition in the SmS crystals was observed both by spectrophotometry and x-ray diffraction. The film optical properties can be modeled with an effective medium calculation. The predicted spectra successfully reproduce the observed qualitative features over a wide range of wavelengths. 相似文献
20.
N. A. Sapoletova N. A. Martynova K. S. Napolskii A. A. Eliseev A. V. Lukashin I. V. Kolesnik D. I. Petukhov S. E. Kushnir A. V. Vassilieva S. V. Grigoriev N. A. Grigoryeva A. A. Mistonov D. V. Byelov Yu. D. Tret’yakov 《Physics of the Solid State》2011,53(6):1126-1130
A method for formation of photonic crystals has been proposed. The method is based on convective deposition of colloidal particles onto vertical substrates in the presence of a direct-current electric field directed perpendicular to the surface of the formed film and an alternating-current electric field applied parallel to the substrate plane. The structure and optical properties of the prepared colloidal crystals have been investigated using scanning electron microscopy, high resolution small-angle X-ray diffraction, and optical spectroscopy. 相似文献