衍射斑 的英文怎麼說
中文拼音 [yǎnshèbān]
衍射斑
英文
diffraction mottle-
Abstract : the far - field spot characteristics of laser converted by random phase plate are analyzed theoretically, including the shape, size, rotational symmetry and diffractive efficiency of the spots, as well as the distribution of subsidiary spot. by comparing the influence of phase element shape ( triangular, square and hexagonal ) on the characteristics, we found that the random phase plate with hexagonal array structure is more suitable for the beam smoothing in laser fusion
文摘:從理論上分析了激光經隨機位相板變換后在遠場的光斑特性（包括光斑的形狀、大小、旋轉對稱性、衍射效率以及旁瓣分佈） ，通過比較三種形狀位相元（等邊三角形、正方形和正六邊形）的遠場光斑特性，得知正六邊形位相元結構的隨機位相板更適合於激光聚變中的束勻化。In this paper we also designed the computer optical elements based on the scalar quantity diffractive theory, which can change the laser beam into a square frame. we mainly refered to the one of those improved algorithms of gerchberg - saxton ( gs ). with the computer simulation and drawing program, the simulated diffraction patterns were gotten in this paper, the results agreed with the anticipated diffraction patterns ; in the paper we also design the computer optical elements that can shape the laser beam into a double circle shape, a lamp shape and so on
計算機模擬成像結果與預期得到的衍射圖樣相符合;文中還討論了設計參數對成像質量的影響規律。同時，本文還用標量理論設計了把高斯光束整形為雙圓斑形光束的計算機光學元件，文中主要是參考改進的gs （ gerchberg - saxton ）演算法;通過計算機模擬，得到了計算機光學元件表面的相位浮雕圖。The influence of changing design parameters on diffractive microlens is investigated. the effects of changing design focal length and microlens material refractive index on diffractive efficiency and airy diffraction disc radius are presented. the numerical results are discussed by qualitative analysis
首先研究了設計參數變化對衍射微透鏡的影響，給出了設計焦距和透鏡材料折射率變化對衍射微透鏡衍射效率、愛里斑半徑等的影響，並對分析結果作了定性討論。The diffraction formula and statistical law of optical fields are used to get the cross - correlation function of intensities of laser speckles of the moved diffuse object
該方法利用光傳播的菲涅爾衍射公式和光場的統計規律，給出散斑場光強在散射體位移前後的高斯光束相關函數的表達式。In the paper, we describe the whole configuration of the joint transform correlator ; introduce the correlative theories of joint fourier transform in detail ; in order to achieve better correlation result, the nonlinear processing of joint transform power spectrum ( jtps ) is put forward, the effect of jtps laplace sharpening and binary processing to the correlation image is given ; the method of the best binary threshold is determined ; we analyse the correlation image, present the way that removes liquid crystal diffraction spot, direct current spot and image noise, and binarize the correlation image finally
本論文主要對提出的聯合變換相關的整體結構進行了描述；詳細介紹了聯合傅里葉變換的相關理論；為了得到更好的相關結果，本文提出對聯合功率譜進行非線性處理的方法，給出了聯合變換功率譜的拉普拉斯銳化和譜的二值化處理對相關峰圖像的影響及二值化最佳閾值的確定方法；對相關峰圖像信息進行了分析；提出了消除液晶衍射光斑、直流光斑和圖像噪聲的方法；最後對相關峰圖像進行了二值化處理。In the experiment, we use the he - ne laser and the semiconductor laser as the source, record the bessel beam patterns behind the axicon by using a digital camera and a microscope, measure the radius of the bessel beam central spot by film - scanning and measure the effect of both the radius of the aperture and the open angle of the axicon on the maximum non - diffraction distance. the experiments show that a specific propagating range has constant power and the beam has a bessel - like distribution in this range. the results agree with the beam corresponding to a diffraction free beam
同時我們還採用膠片掃描的方法測量了無衍射光束的中心光斑尺寸，測量了不同光闌孔徑和不同稜角情況下的最大無衍射距離和傳播軸附近橫截面內微小光孔中的光強，實驗結果顯示當激光光束經過軸棱錐轉換後有一段距離功率變化很小，且分佈近似貝塞爾分佈，符合無衍射光束的特性;經過聚焦后，呈現三維分佈中空的光束bottlebeam ，實驗結果與理論分析基本吻合。The main works and contributions achieved in this dissertation are concluded as follows : 1. based on the scalar diffraction theory, the mathematical model of optical configuration of transmissive grating interferometer is established. it indicats that moir interference fringes is affected by many parameters, such as grating pitch, light wavelength, light beam size and incidence angle, etc. the variation that the width, intensity, orientation and contrast of moir interference fringes along with every parameter is numerically analyzed
主要的研究內容和所取得的成果可歸納如下: 1 .基於標量衍射理論，建立了透射式光柵干涉儀光路的數學模型，分析了透射式光柵干涉儀的莫爾干涉條紋與光柵柵距、光柵開口比、光波波長、光斑尺寸、光束入射角等多個參數的關系。A cyclic radial shearing interferometer was used to diagnose the wavefront distortion of a laser system and an lcslm ( liquid crysnd spatial ligh modulator ) was used to control it. some results have been summarized as follows : l. according to the theory of scalar quanity diffeaction and the model of the random gaussian phase screen of low frequency wavefront, the effect of the low frequency wavefront with different rms gradient on the focal spot of a laser beam was studied
本論文在激光光束波前畸變檢測和控制上進行了新的探索，主要就空間相位調制環路徑向剪切干涉儀以及它對波前畸變的檢測和液晶空間光調制器及其對中頻段波前畸變的控制進行了研究，其研究的內容和取得的成果如下：一、根據標量衍射理論，結合低頻波前畸變的高斯隨機位相分佈模型，研究了不同均方根梯度低頻畸變波前對激光光束焦斑聚焦性的影響，並採用描述中頻段波前畸變的功率譜密度概念，模擬計算了它對激光焦斑旁瓣的貢獻。In order to analyze the effect of aberration of amplitude and phase of laser beam on centroid position of focal spot, based on the fraunhofer formula for light wave scaler diffraction theory, according to the definition of first order moment centroid position, the general expression of focal spot centroid position directly depending on the complex amplitude of near field is derived
摘要為分析振幅和相位發生畸變情況下光束焦斑質心位置所受的影響，以光波標量衍射理論中的夫瑯和費衍射公式為基礎，根據光斑強度分佈一階矩質心位置的定義，推導了直接依賴于光束近場復振幅分佈的焦斑質心位置的一般表達式。The extracted height - height correlation function and the random surface parameters obtained ever since conform with those obtained by the measurement of afm in chaper 3, based on the light scattering theory of kirchoff approximation, we propose the method for the extraction of surfaces parameters from the correlation functions of speckles intensity produced by light scattering in the region near the random surfaces
我們以對三個高斯相關的隨機表面樣品的實驗測量為例，對該方法行了驗證。所測得的結果與用原子力顯微鏡測量的結果符合得很好。第三章根據基爾霍夫近似下的光散射理論，提出了從隨機表面附近衍射區內的散斑場相關函數中提取隨機表面參量的方法。During the experiment of protein crystal growth in space carried by chinese re - entry capsule fsw - 2, the crystals of barheaded goose hemoglobin suitable for x - ray analysis were obtained both in space and earth as contrast group. the diffraction data of both crystals were collected, and the structures were solved using molecule replacement methods. the comparison of structures in space and earth indicate that, the interactions among molecules in crystal and subunits of molecule in space is weakened relative to the crystal on earth, there is a contact in the
在1994年我國返回式衛星fsw - 2上進行的空間蛋白質晶體生長實驗中，獲得了適合於x射線分析的空間實驗組和地面對照組的斑頭雁血紅蛋白晶體，並收集了x射線衍射數據。應用分子置換法解析了結構，並進行了比較研究。結果顯示空間晶體的分子間和分子中亞基間的相互作用趨于減弱，在This paper analyses light energy of fraunhofer diffraction of circular hole, and proves that the energy of airy disk is 84 % of light energy of normal incidence
摘要對圓孔夫瑯禾費衍射光能量進行了定量分析，並證明了愛里斑能量?入射光能量的84 % 。The matlab program is used to reconstruct the image of objects and by several ways of digital image - processing such as band - pass filtering and v - filtering, the quality of reconstruction image is greatly improved
利用帶阻濾波和v型濾波等數字圖像處理方法削弱了零級衍射斑的影響，提高了再現像質量。At the s ame time, an exceptional structure has been found in the sample annealed for one hour at 800. it appears the single crystal lattice irradiated by high - energy electron beam within a few seconds and then becomes amorphous structure quickly
同時在800退火1小時的薄膜中發現一種異常結構，在短時間高能電子束照射下呈現明晰的單晶衍射斑點，但時間一長，非晶化現象嚴重。In fact, hartmann - shack wavefront sensor is affected by the noise of ccd and the constructed error too. in our compare, a bridge is setup, which is the original wavefront composed by zernike polynomial, we transform the original wavefront into far field. then we can compare the accuracy of hartmann - shack wavefront sensor with the accuracy of the system of far field diagnosis in detecting the farfield, using diffraction limit and encircle energy
我們在進行兩者相互比較的過程中，搭建了一個比較的橋梁，即由zernike多項式組成的各種原始像差波前，將它也變換到遠場作為原始理想遠場光斑，然後，以它的衍射極限和環圍能量曲線作為評價標準，比較hartmann - shack波前傳感器和遠場測量系統在光束質量診斷中的探測精度。Numerical results show that the top - hat beam stl instrument is more sensitive than the gaussian beam stl instrument, with a maximum sensitivity enhancement factor of approximately 2. 3
測量了信號的衍射分佈，信號與激勵光功率、激勵光斑半徑、調制頻率、探測距離的關系，與理論吻合較好。Based on the rate - equation theory of four - level system, the expressions of threshold pump power, output power and slope efficiency are given. the influence of space distribution of pump light ( the position of focusing point, dimension of pumping light and divergence angle ) to the output characteristics are also discussed. then, by investigating the effects of thermal effect of laser crystal on the size of laser cavity mode, we obtain the mode - matching principle of high power laser diode end - pumped solid - state lasers
其中，在泵浦光的空間分佈變量中我們分別考慮了泵浦光聚焦后的腰斑大小、聚焦腰斑在增益介質中的位置以及泵浦光在介質中發散角的影響；然後我們研究了在高泵浦功率下激光晶體因吸收泵浦光而產生的熱效應所導致的熱透鏡效應以及熱致衍射損耗，通過分析它們對振蕩激光腔模尺寸的影響，得到了高功率半導體激光二極體端面泵浦固體激光器模式匹配的要求，為高功率連續單頻nd ： yvo _ 4激光器的優化設計提供了理論依據。If the single - slit is replaced by a small hole, because of the diffraction by the small hole, a bright spot appears on the screen surrounded with gradually decreasing bright and dark stripes alternating with each other, for which the intensity distribution is as follows, refer to figure 1 - 2
如果單縫變成小孔，由於小孔衍射，在屏幕上就有一個亮斑，它周圍還有逐漸減弱的明暗相間的條紋，其強度分佈如圖1 - 2所示。分享友人