共查询到20条相似文献,搜索用时 15 毫秒
1.
Jingchang Sun Hongwei Liang Jianze Zhao Ziwen Zhao Guotong Du 《Applied Surface Science》2007,253(11):5161-5165
ZnO films were deposited on c-plane Al2O3 substrates by pulsed laser deposition. The etching treatments for as-grown ZnO films were performed in NH4Cl aqueous solution as a function of NH4Cl concentration and etching time. It was found that NH4Cl solution is an appropriate candidate for ZnO wet etching because of its controllable and moderate etching rate. The influence of etching treatment on the morphology, optical and electrical properties of the ZnO films has been investigated systematically by means of X-ray diffraction, atomic force microscope, photoluminescence and Hall effect. The results indicated that the surface morphology and optical properties of the films were highly influenced by etching treatment. 相似文献
2.
《Infrared physics》1983,23(3):149-156
This paper treats theoretically the coupling losses which arise in square dielectric waveguide CO2 lasers when one element of the optical resonator is a diffraction grating. These losses are due to imperfect coupling of the radiation which is launched from the end of the guide to the grating and returned from the grating back to the guide. The results of the calculations show that the coupling efficiency is a sensitive function of radiation wavelength. This result is then used to investigate the ability of a 150 lines/mm diffraction grating to resolve adjacent rotational-vibrational transitions in the CO2 emission. It is shown that “line-hopping” places a limitation on the maximum tunability which can be obtained and is a result of the poor discrimination at the grating surface especially in the case of waveguide lasers having much reduced apertures. Computations based on the scaling laws are employed to maximise the tunability as a function of waveguide aperture taking into account limitations imposed by “line-hopping”, cut-off and the optical resonator frequency offset condition of c/4L. Comparisons are made between theory and experiment, and design guidelines for the construction of widely tunable CO2 waveguide lasers are presented graphically. 相似文献
3.
4.
为了在光学薄膜中引入连续轮廓的微结构,综合利用薄膜的干涉效应与微结构的折反射、衍射效应,提出一种薄膜光学微结构的制备工艺。基于时域有限差分方法设计了具有可见光波段减反射特性的薄膜光学锥形光栅;采用单点金刚石车削技术,结合纳米压印与电感耦合等离子体刻蚀技术,在SiNx薄膜中制备出高1.6 μm,周期4.1 μm的锥形光栅;在可见光波段,SiNx薄膜光学锥形光栅的平均反射率为5.7%,反射率的实验检测结果与仿真计算结果达到很高的一致性;当入射光角度在30°以内,薄膜光学锥形光栅的减反特性表现出对光波入射角度的不敏感性。该制备工艺突破了单点金刚石车削技术的材料局限,将连续轮廓的微结构的直接形成工艺拓展至介质薄膜当中,实现了宽光谱、宽入射角度的减反射。 相似文献
5.
J.J. Carvajal M.C. Pujol M. Aguiló J.R. Vázquez de Aldana P. Moreno T. Trifonov R. Alcubilla J. Ferré-Borrull L.F. Marsal R. Macovez 《Journal of luminescence》2009,129(12):1441-1447
We revisited two different strategies to fabricate 1D photonic crystals of nonlinear optical dielectric materials based on ultrafast laser ablation of the surface of an RbTiOPO4 crystal, and selective etching of ferroelectric domains of the surface of a periodically poled LiNbO4 crystal. We evaluated their behaviour as Bragg diffraction gratings. We also presented the recent advances we developed in a new procedure of fabrication of 2D and 3D photonic crystals of KTiOPO4 (KTP) grown on the surface of a KTP substrate by liquid phase epitaxial means within the pores of a silicon macroporous template. Optical, structural, morphological, and compositional characterization for the photonic crystals produced through this technique are presented. 相似文献
6.
Phase diffractive optical elements are at present proposed for use with infrared high power lasers, for material surface treatment applications. However, the heating of the component exposed to several kilowatts per square centimetre can be a problem for practical implementation. The deformations due to thermal expansion of a gold binary diffraction grating under high power CO2 laser exposure at 10.6 μm are estimated by a Finite Element Method. They are compared to the geometrical tolerances obtained by a rigorous electromagnetic Fourier modal method which is used to calculate the optical performances. Several exposure parameters (duration, average laser power) and grating parameters (period, line space ratio) are investigated. The laser exposure should be limited to a few milliseconds with a power density on the grating of 104 W/cm2, so that the amplitude of the deformations does not exceed the 75 nm tolerance on the grating depth. One is thus assured that the diffraction efficiency in the first order remains superior to 38.5%. 相似文献
7.
Oleg Babchenko Alexander Kromka Karel Hruska Miroslav Michalka Jiri Potmesil Milan Vanecek 《Central European Journal of Physics》2009,7(2):310-314
We report the use of gold, nickel and diamond nanoparticles as a masking material for realization of diamond nano-structures
by applying the dry plasma etching process. Applying low power plasma (100 W) in a gas mixture of CF4/O2 for 5 minutes results in a formation of three different types of diamond nanostructures, depending on the mask type material
and particle size. Using of the Ni mask results in realization of diamond nano-rods, applying of the Au mask brings cauliflower-like
structures, and using the diamond powder allows the production of irregular nano-structures. The main advance of the presented
etching procedure is use of a self-assembly strategy where no lithographic steps are implemented.
相似文献
8.
D. V. Roshchupkin D. V. Irzhak S. L. Shabel’nikova A. A. Firsov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(4):663-666
The X-ray optical properties of diffraction gratings fabricated on the basis of a Si(400) crystal with a period of D = 1 μm are studied by triple-crystal X-ray diffractometry. The diffraction gratings are manufactured both by silicon profiling during the process of plasma chemical etching and by forming a phase-shift grating on the surface of a Si crystal. The principal difference in the diffraction properties of these gratings is demonstrated. The presence of an Au phase-shift grating is shown to lead to the formation of a two-dimensional diffraction pattern, whereas Si profiling leads to the formation of only a one-dimensional diffraction pattern. 相似文献
9.
Downstream mass spectrometry is successfully used in the reactive ion-beam etching of dielectric diffraction gratings of deep grooves with vertical sidewalls to achieve in situ endpoint detection. Silica (SiO2) gratings with a Sc2O3 etch-stop layer are fabricated by reactive ion-beam etching with CHF3 as etchant, and the mass spectrometric signal of SiF3+ produced by the reactive etching of the SiO2 grating material is monitored. When the etch-stop layer is reached, a drop of this signal occurs. By comparing the monitoring curves and resulting gratings of different etching methods, we find that the decrease of the monitored signal is strongly influenced by the sidewall steepness of the etched grating grooves. All conditions being equal, the greater sidewall steepness renders the faster decrease of the signal. Consequently, the proposed approach of endpoint detection applies well to the gratings with steep sidewalls. With the help of two previously developed methods, the sidewall steepness of grating grooves is increased, and the optimal endpoint is detected. Employing the proposed technique, we have reproducibly fabricated dielectric gratings with proper groove depth and even groove bottom. 相似文献
10.
Zhifeng Zhang Huanghuang BaiGuishuan Yang Fengchun JiangYufen Ren Junfeng LiKun Yang Hongjun Yang 《Optik》2013
In this paper, we describe a novel computer simulation technique of generating Fraunhofer diffraction images from different patterns. The simulation can be performed in almost any PC using the software MATLAB. The patterns of five types of elements, including one slit, one rectangular aperture, two rectangular apertures, the grating and one circular aperture are discussed and simulated. Diffractions images can be generated for any wavelength of light and for any program are presented. Finally, the Fraunhofer diffraction optical intensity distribution is analyzed. Simulation results can improve the physics experimental teaching of Fraunhofer diffraction. The programs based on MATLAB have been used as the platform to real-time calculation and simulation and solve the optical problem. 相似文献
11.
A. V. Khomich M. V. Kanzyuba I. I. Vlasov V. G. Ral’chenko N. I. Gorbachuk 《Journal of Applied Spectroscopy》2011,78(4):563-571
We have studied the IR absorption spectra of samples of porous ultrananocrystalline diamond (UNC diamond) obtained by selective
etching of the sp
2 phase in UNC diamond films. We show that the surface of porous UNC diamond is polyfunctional. We have studied the behavior
of surface hydride, carbonyl, carboxyl, and hydroxyl groups as a function of annealing temperature in air and the time kept
under normal conditions for UNC diamond films previously oxidized at 430°C–450°C. In the range from a few minutes to a few
months, we studied the kinetics for establishment of the steady state for the functional adsorbed layer on the diamond surface
under normal conditions. The observed growth in the intensity of the transmission bands due to hydride (CH
x
) and other hydrogen-containing functional groups is explained by dissociation of water molecules on the surface of the UNC
diamond films. 相似文献
12.
P. S. Chung 《Optics & Laser Technology》1983,15(5):263-268
We present a detailed design of a 3-dB TE0-TE1 micro-optical mode converter using a chirped grating to phase-match the two propagation modes in an optical waveguide. Devices were fabricated in titanium in-diffused lithium niobate by ion-beam etching the tapered grating pattern into the waveguide surface. The power transfer between the two coupled modes was observed experimentally by varying the angle between the light beam and the normal grating wave-vector. Insertion loss of the TE0-TE1 mode converter due to spurious scattering was estimated at 1.5 dB. 相似文献
13.
A. M. Nastas A. M. Andriesh V. V. Bivol A. M. Prisakar G. M. Tridukh 《Technical Physics》2009,54(2):305-308
Recording of optical holographic gratings based on photostructural transformations in thin (≈ 1 μm) As2S3 and As2S3 semiconductor layers in the presence and absence of a corona discharge and also chemical etching of these gratings are studied.
Initiation of a corona at the stage of interference grating recording is shown to improve the exposure contrast of metal-glassy
chalcogenide semiconductor thin-film structures. The holographic sensitivity, diffraction efficiency, dynamic range, and contrast
are also improved severalfold. When phase relief gratings formed in these layers are selectively etched in a chemical etchant
in the presence of a corona, their profile becomes more regular and deeper by 25–30% and the diffraction efficiency increases
by 30–50%. 相似文献
14.
多层介质膜光栅是高功率激光系统的关键光学元件. 为了满足国内强激光系统的迫切需求,首先利用考夫曼型离子束刻蚀机开展了HfO2顶层多层介质膜脉宽压缩光栅的离子束刻蚀实验研究. 采用纯Ar及Ar和CHF3混合气体作为工作气体进行离子束刻蚀实验,获得了优化的离子源工作参数. 结果表明,与纯Ar离子束刻蚀相比,Ar和CHF3混合气体离子束刻蚀时的HfO2/光刻胶的选择比大. HfO2的离子束刻蚀过程中再沉积效应明显,导致刻蚀光栅占宽比变大. 根据刻蚀速率分布制作的掩模遮挡板可以提高刻蚀速率均匀性,及时清洗离子源和更换灯丝,可保证刻蚀工艺的重复性. 利用上述技术已成功研制出多块最大尺寸为80 mm×150 mm、线密度1480线/mm、平均衍射效率大于95%的HfO2顶层多层介质膜脉宽压缩光栅. 实验结果与理论设计一致,为大口径多层介质膜脉宽压缩光栅的离子束刻蚀提供了有益参考.
关键词:
光栅
多层介质膜
离子束刻蚀 相似文献
15.
We present a new idea of marking based on spectral properties of CO2 laser radiation. The idea has been illustrated on RF excited waveguide CO2 lasers in different configurations: single channel, multi-waveguide and slab-waveguide ones. The pulse operation of the laser has been considered as well. The advantage of the presented diffraction marker is avoiding complicated and fallible mechanical elements. The only executive elements of the marker are a diffraction grating and a piezoceramic transducer. It has been shown that the slab-waveguide configuration of the RF excited CO2 laser equipped with an unstable resonator is the most promising configuration for application to the diffraction marker. 相似文献
16.
T. N. Smirnova O. V. Sakhno V. I. Bezrodnyj J. Stumpe 《Applied physics. B, Lasers and optics》2005,80(8):947-951
In this letter we report a simple technique to produce volume holographic gratings based on photopolymerizable composites containing TiO2 nanoparticles. Diffraction gratings with high refractive index modulation amplitude (up to 1.25 × 10−2) have been formed due to the periodic distribution of high refractive index nanoparticles in a low refractive index polymer matrix. The diffraction efficiency increases strongly on increasing the nanoparticle concentration. Taking the mixture with 10 wt.% TiO2 nanoparticles, gratings with high diffraction efficiency, low level of scattering and high transparency in the visible-wavelength range have been obtained. This will ultimately lead to different applications of diffractive optical elements based on nanocomposites. The dependence of the gratings’ diffraction efficiency on the intensity of probe laser pulses at 1064 nm has been explored. It is shown that the nonlinear response of the gratings is attributed mainly to the nonlinear properties of the TiO2 nanoparticles embedded in the polymer matrix. The mechanism of the grating formation and the reasons for the nonlinear behavior of the diffraction efficiency are discussed. 相似文献
17.
多层介质膜光栅是高功率激光系统的关键光学元件.为了满足国内强激光系统的迫切需求, 在大口径多层介质膜光栅的研制过程中,建立了单波长自准直条件下的衍射效率测量方法及其误差分析. 结果表明误差主要由探测器的噪声和测试人员的差异产生,对衍射效率测试精度的影响是±1%. 在此基础上,将光栅衍射效率及其分布测量技术应用于光栅制作工艺中, 作为大口径光栅无损检测的一种手段,如判断光栅掩模是否能进行离子束刻蚀、 离子束刻蚀的在线监测和是否需要再刻蚀,从而实现对大口径多层介质膜光栅离子束刻蚀过程的定量、 科学控制,提高了离子束刻蚀光栅制作工艺的成功率.利用上述技术,已成功研制出多块最大尺寸为 430 mm× 350 mm、线密度1740线/mm、平均衍射效率大于95%的多层介质膜光栅. 实验结果表明,该方法操作简单、测量快速准确,不必检测光栅微结构. 为大口径多层介质膜光栅研制的无损检测工程化奠定了基础. 相似文献
18.
G.A. Shafeev E.D. Obraztsova S.M. Pimenov 《Applied Physics A: Materials Science & Processing》1997,65(1):29-32
2 O, (CH3)2SO). Diamond samples are virtually transparent at this wavelength, and the coupling of laser radiation to diamond is via the
formation of a thin graphitized layer at the diamond surface. The etching rate in liquid media is slightly higher than in
air at otherwise equal conditions and is as high as 50 μm/s for etching with a scanning laser beam. Raman spectra measurements
carried out on diamond samples etched in air show the presence of glassy carbon on the surface, whereas for samples etched
in a liquid the diamond peak at 1332 cm-1 dominates with significantly lower intensity of the glassy carbon peak. Electroless copper deposition on the laser-etched
features is studied to compare the catalytic activity of the diamond surface etched in air with that etched in liquids. Possible
mechanisms responsible for the observed difference both in the structure of the etched area and in the electroless Cu deposition
onto the surface etched in various media (air or liquids) are discussed.
Received: 2 August 1996/Accepted: 7 January 1997 相似文献
19.
《Journal of Physics and Chemistry of Solids》2007,68(5-6):1008-1013
The paper is focused on the possibilities of selective wet etching of optically and thermally crystallized/amorphous Ag-doped chalcogenide thin films, namely Agx(As0.33S0.67)100−x and Agx(As0.33S0.335Se0.335)100−x. The selective etching of optically(thermally) crystallized Agx(As0.33S0.67)100−x and thermally crystallized Agx(As0.33S0.335Se0.335)100−x thin films in water solution of NaCN is presented. The good surface quality is an important and crucial parameter for optical elements fabrication (e.g. grids, waveguides, etc.) especially in nanometer dimensions. The selective etching of undoped and Ag optically doped region was also carried out to observe surface roughness of doped region before and after selective etching. Characterization of the structure and surface of studied films by Raman spectroscopy, X-ray diffraction, AFM and SEM methods has been done and potential application suggested. 相似文献
20.
The transfer of continuous-relief diffractive structures from resist into diamond by use of direct-write electron-beam lithography followed by dry etching in an inductively coupled plasma is demonstrated. The gases used for the diamond etching are O(2) and Ar. The chemical-vapor-deposited diamond substrate is of optical quality. Our results show that the transfer process generates fairly smooth etched structures. Blazed gratings with periods of 45mum and Fresnel lenses have been manufactured. The blazed gratings have been optically evaluated with a femtosecond laser operating at 400 nm. The diffraction efficiency was 68% in the first order, with a theoretical value of 100%. We intend to investigate the transfer process further and then to fabricate diffractive and refractive elements for use with Nd:YAG high-power lasers. 相似文献