激光射閾 的英文怎麼說
中文拼音 [jīguāngshèyù]
激光射閾
英文
lasing threshold- 激 : Ⅰ動詞1 (水因受到阻礙或震蕩而向上涌) swash; surge; dash 2 (冷水突然刺激身體使得病) fall ill fr...
- 光 : Ⅰ名詞1 (照耀在物體上、使人能看見物體的一種物質) light; ray 2 (景物) scenery 3 (光彩; 榮譽) ...
- 射 : Ⅰ動詞1 (用推力或彈力送出) shoot; fire 2 (液體受到壓力迅速擠出) discharge in a jet 3 (放出) ...
- 閾 : 名詞1. [書面語] (門坎兒) threshold; doorsill2. (界限; 范圍) threshold
- 激光 : [物理學] laser 激光靶 laser target; 激光報警器 laser avoidance device; 激光玻璃纖維 laser fibre; ...
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The electronic temperature, intensities of all lines and continuous spectra gradually increased with the increment of laser energy, and they got to maximum at different laser energy. our results of copper and aluminum show that there are possibly different thresholds of laser energy to electronic temperature and intensities of emission spectra of laser ablated plasma. at the different environmental gas pressure, spatial emission intensity distribution is explained by the competition among " heat reservoir effect ", " confined effect " and " s hadow effect "
認為cu等離子體羽的發光機制是由電子與粒子的碰撞傳能、電子與離子的復合形成的;隨激光能量的增加, cu等離子體特徵輻射(分立譜) 、連續背景輻射(連續譜) 、電子溫度都出現最大值;結合對al的實驗結果說明:激光燒蝕金屬產生的等離子體,其特徵輻射、連續輻射、電子溫度可能都存在一定的能量閾值;背景氣壓對激光燒蝕等離子體譜線的影響,其機理可以認為是「熱庫效應」 、 「約束效應」及「陰影效應」相互競爭的綜合結果。This paper summarized several main research methods on this topic in our country, including " the determinant of laser - induced - damage of thin film by the scan of transmission and reflectance method ", " study of the phenomena on laser - induced thin film damage by photo - acoustic method " and " the measurement of damage threshold on optical thin film by diffusion method ", etc
本文總結了目前國內幾種主要的研究方法,包括用透射反射掃描法檢測光學薄膜的激光損傷,用光聲法測定光學薄膜的破壞閾值,以及用散射法來測量光學薄膜的損傷閾值等。The effects of air ' s absorption of heat, scatter, turbulent and thermal blooming on the laser beam transmitting under the air breakdown threshold value are analysed when laser transmit in the air and the result can be used designing of the laser system
摘要系統分析了激光在大氣中傳輸時在擊穿閾值以內,由於大氣汽溶膠的吸收、散射、大氣湍流、大氣熱暈等線性非線性問題對光束控制系統的影響,為激光系統提供指導。The relation between area of ccd saturation and 0. 632 m 、 1. 06 m laser power / energy was measured. the ccd camera was disturbed by strong radiation from laser outside the field of view in experiment. the relation between the area of ccd saturation and off - axis angle was measured
通過實驗,得到激光干擾ka - 320型面陣ccd光電探測器的像元飽和閾值、探測器靶面飽和閾值、局域損傷閾值,並得到了0 . 632 m與1 . 06 m波段入射激光功率與ccd靶面飽和程度的對應關系曲線,了解了面陣ccd探測器受激光干擾的各個階段。In this thesis, we demonstrate the study of si - based light emitting materials and its importance in si - based photonics integration. we discussed mainly the gain, differential gain, threshold current of si - based quantum - dot laser and the dependence of threshold current on temperature from discrete energy level of three - dimension confined quantum - dot and state density distribution of 5 - function
本文闡述了si基光發射材料的研究進展及它在硅基光電子集成中的重要地位,從三維受限量子點的分立能級和函數狀的態密度分佈入手,著重討論了si基量子點激光器的增益、微分增益、閾值電流及閾值電流的溫度特性。Vertical - cavity surface - emitting lasers ( vcsel ' s ) have distinct advantages over conventional edge emitting lasers, such as small divergence angle, single longitudinal mode operation and very low threshold current. they are especially suitable for making two - dimensional ( 2 - d ) arrays as well as vcsel ' s based integrate devices
垂直腔面發射半導體激光器( vcsel )與傳統的邊發射半導體激光器相比,它具有發散角小、單縱模工作、非常低的閾值電流等優點,尤其它適於二維面陣集成和與其它光電子器件集成。At first, bubble flow image is acquired using laser and incandescence lamp respectively as light source and using ccd. according to different optics - dispersion character, threshold segmentation method is proposed to identify gas from the gas - water flow, which make steadfast base for further calculate void fraction. the precision of threshold directly affect the calculate precision of void fraction
文中分別採用激光片光源和影視燈照明,採用逐行掃描數字ccd攝像機獲取氣泡的流動圖像;根據氣泡和水對光的反射特性不同,提出採用閾值法識別圖像中的氣泡和水,從而為進一步計算摻氣濃度打下堅實的基礎。The character of fiber laser spectrum is measured by optical spectrum analyzer. the experiment approves the relationship of loss, threshold and lasing wavelength, which is that the higher loss, the higher threshold, and the shorter lasing wavelength
我們用光譜儀測量了激光光譜特性,實驗研究了腔損耗及閾值和激射波長的關系,即損耗越大閾值越高,激射波長越短。In this paper, micro - cavity semiconductor laser ( mcsl ) with pillar vertical - cavity surface - emitting structure ( vcsel ) which has potential applications in optical communication and optical interconnect is theoretically analyzed, the calculation model that used to discuss the modal performance of rectangular columnar and cylinder vcsel with oxidized aperture is established by using vector field model. the numerical simulations in the case of cylinder structure show oscillating wavelength and threshold gain against inside and outside radius of laser, the layer refractive index and pair number of bragg mirror, thickness, position and oxidized material ' s refractive index of oxidized aperture, in detail. more practically, considering dos shell of laser as non - perfect one, or supposing that dos shell is separated from the laser, we can obtain more significative results
本工作以矢量場模型出發,對具有誘人應用前景的柱形垂直腔面發射結構( vcsel )的微腔半導體激光器( mcsl )進行了理論分析,建立了用於分析方柱形和圓柱形結構具有氧化孔徑層的激光器的模式特性的理論模型;對圓柱形結構情況進行了數值模擬,得到了振蕩波長、閾值增益隨激光器內外半徑、 bragg反射鏡層折射率、周期數以及氧化孔徑層厚度、位置和氧化物折射率的詳細變化規律;為使理論計算更接近實際,將外加金屬包殼視為非理想導體,或將金屬包殼與激光器結構隔開,分別對這兩種情況下的結果進行了討論。Optics and optical instruments - preparation of drawings for optical elements and systems - laser irradiation damage threshold
光學和光學儀器.光學元件和系統制圖準備.激光輻射損害閾The epitaxial struture for ld is an ingaas / gaas / algaas ssqw grin sch structure and the width of the array bar ia 4mm. the low theshold current 2. 9a the output power 20w at 17. 5a have been achieved by sioi isolation, ohmic contact and facet coating processes. the central wavelength is 979nm. at the same time, model analyses on the structure of the ssqw ld and the fabrication processes have been made for further research
激光器的生長結構採用ingaas / gaas / algaas分別限制應變單量阱線性緩變折射率波導結構,列陣條寬為4mm ,通過sio _ 2掩膜,歐姆接觸和腔面鍍膜等工藝,實現了閾值電流為2 . 9a ,驅動電流為17 . 5a時輸出功率為20w 。The main work can be summed up as follows : firstly, we studied the thermal - field properties of vcsels, and analyzed the influences of current spreading, material parameters and operating conditions on the temperature distributions. secondly, we began with the electrode voltage and calculated the equipotential s distributions, compared the distributions of voltages and current densities in different depths of vcsels, and then studied the influences of the oxide - confining region with different position or thickness, and the different sizes of the gain - guided aperture and emitting window on the distributions of the injected current density, carrier concentration and temperature in the active region. thirdly, we realized the coupling of electricity, optical and thermal - fields, worked out the threshold voltage, calculated the distributions of the injected current density, carrier concentration and temperature under different offset voltages, and analyzed the impacts of temperature profile and carrier density on the refractive index, fermi levels and optical - field
具體工作可以概括如下:首先,研究了vcsel的熱場特性,分析了電流擴展,材料參數和工作條件對于溫度分佈的影響;其次,從電極電壓入手,計算出激光器中的等勢線分佈,並對不同深度處的電壓和電流分佈進行比較,研究了高阻區的不同位置和不同厚度、限制層和出射窗口半徑的大小對電流密度、載流子濃度和溫度分佈的影響;再次,實現了電、光、熱耦合,求出了閾值電壓,計算了不同偏置電壓下的電流密度分佈、載流子濃度分佈和熱場分佈,分析了溫度和載流子濃度變化對折射率、費米能級和光場的影響;最後,給出了考慮n - dbr和雙氧化限制層時激光器中的等勢線分佈,分析了n - dbr和雙氧化限制層對vcsel電流密度、載流子濃度、溫度和光場分佈的影響。Based on these foundations, we give a perfect scheme of the bbo opos : single pass amplification coefficient of the opg under different pump intensity is calculated ; collinear type - i and type - ii phase matching tuning curve pumped by the q switch nd : yag various harmonics as well as noncollinear type - i tuning curve are calculated in details ; the effect of the walkoff for the nonlinear effect coefficient and the group velocity matching are analyzed ; the acceptance angle in parametric process is calculated ; the numerical threshold of the bbo opo is calculated ; the process of the saturation and depletion of the pump beam are analyzed ; the relationship of the conversion efficiency and reflectance of output mirror are discussed ; various linewidth controlling methods are discussed ; the improvement of the beam quality applying the unstable cavity is discussed ; and the crystal bbo design is considered
在此基礎上,給出了一整套bbo - opo激光參數設計方案:計算了不同泵浦強度下的參量放大倍數;詳細計算了在nd : yag調q激光器各次諧波泵浦條件下的共線類和類相位匹配的調諧曲線,以及非共線類相位匹配調諧曲線;分析了走離角對非線性系數和群速匹配的影響;計算了參量過程的允許角;計算了bbo - opo的理論閾值條件;分析了飽和與泵浦光束的消耗過程;給出了轉換效率與超過泵浦閾值的倍數的關系;討論了轉換效率與輸出鏡反射率的關系;討論了線寬控制的各種方法;研究了利用非穩腔改善光束質量的方法;考慮了bbo晶體的設計。By use of g. d. shen ' s tunneling cascade theory we have fabricated high performance and high power tunneling cascade ingaas / gaas / algaas 950nm / 990nm double wavelength strained quantum well lasers on the basis of former tunneling cascade high power lasers and high brightness light emitting diodes. the lasers " two peak wavelength are 95 ? nm and 990 ? nm. el spectrum ' s fwhm is 3nm
在以往隧道級聯大功率應變量子阱激光器及高亮度發光管的理論研究與實驗的基礎之上,採用沈光地教授提出的隧道級聯思想,成功研製出基於ingaas gaas algaas材料的高性能大功率隧道級聯950nm及990nm雙波長應變量子阱激光器,激射波長分別為952 2nm和990 2nm , el譜的譜線寬度約3nm ,未鍍膜器件單面最大輸出光功率可達2w以上,閾值電流最低達120ma 。The principle advantages of vcsels over conventional edge - emitting lasers lie in ultralow threshold current, small far - field divergent angle, high modulation frequency, potential for wafer level testing and the ease for single longitudinal mode operation and two - dimension integration. as a result they show considerable promise for applications such as optical fiber communication, parallel optical interconnects, optical information processing and neural networks, etc. a direct coupling theoretical model in quasi - three - dimension for the gain - wave guide vertical - cavity surface - emitting lasers has been created in this paper
它與傳統的邊發射激光器相比具有更優越的特性,例如,具有極低的閾值、較小的遠場發散角、調制頻率高、易實現單縱模工作和二維集成,無須解理封裝即可進行在片測試等,所以,它被廣泛應用於光纖通訊、并行光互聯、光信息處理、光神經網路等領域。Adopting the amendatory rate equation, the threshold of the micro - cavity has been studied and the conclusion is shown as following : if there is not non - radiation transition, the pump velocity just need to compensate the photon velocity escaped from the cavity, and the intensity of output light will direct ratio to the intensity of input light then we got a micro - cavity laser with no threshold
採用修正的速率方程對微腔激光器的閾值進行研究,得到如下結論:在沒有無輻射躍遷時,激光器的泵浦速率只需恰好補償光子向腔外的逃逸速率,輸出光強隨著輸入泵浦光強性線增加,實現所謂的「無閾值」激光器。In this paper, some investigation and design as following. have been carried out on er - yb codoped phosphate glass waveguide laser first, three primary performance parameters of er - yb waveguide laser pump threshold power ; output power and slope efficiency have been commulated and analysed theoretically based on er ~ ( 3 + ) - yb ~ ( 3 + ) energy configuration ; rate equation of stable state and transmitting equation. the influences of er - yb ions concentration ; enabled waveguide length ; light dot radius of signal light and pump light ; reflectivity of output lens on three above parameters have been researched
首先,從er ~ ( 3 + ) - yb ~ ( 3 + )能級結構出發,結合激光穩態速率方程與傳輸方程,對鉺鐿波導激光器的三個主要性能參數:閾值功率、輸出功率、斜率效率作了理論計算分析,並研究了鉺、鐿離子濃度、光波導激活長度、信號光與泵浦光光斑半徑比例、輸出耦合鏡反射率對這三個關鍵性能參數的影響。So the conventional solid windows have been becoming the threshold of the laser energy ' s promotion and the optical quality ' s improvements. to solve the above - mentioned problem of hel ' s output solid windows the concept of aerodynamic windows ( abbr. adw ) is proposed according as the property of gas, i. e
由於氣體介質具有對電磁輻射選擇吸收的特性,而且其擊穿功率閾值也特別高,因此為了解決上述高能激光器固體輸出窗口的「瓶頸」問題,根據氣體介質的這一特性,提出了氣體動力學輸出窗口(簡稱為氣動窗口, adw )的解決方案。The analyses given in this paper to quasi - three - level for 946 nm laser are complete. the relation between 946 nm laser transmission and optimal crystal length has been derived from the rate equations describing the population inversion and the photon density in the laser cavity in the steady - state case. the minimal claims to coating have been given on the base of contrasting 946 nm transmission with 1064 nm transmission in the condition of different cavity losses and how the pump beam radius in the laser crystal and optimal crystal length affect the laser threshold and output power of 946 nm laser has been given as well
對產生946nm譜線的準三能級結構給出了較為完整的分析,利用激光諧振腔處于穩態時的速率方程,導出了準三能級nd : yag946nm起振時,透射損耗與最佳激光晶體長度的關系,在與1064nm透射損耗相比較的基礎上,給出了不同的腔損耗情況下的最低鍍膜要求,並且給出了激光閾值、輸出功率和最佳激光晶體長度及泵光光斑大小的關系,這為設計室溫下高效運轉的946nm激光器的提供了理論基礎,這種分析方法對研究此類低增益,準三能級或三能級激光系統輸出特性有借鑒意義。Compared to gan, which is one of the most successful wide - band semiconductor materials at present, zno is promising : high - quality zno with very low defect densities can be synthesized at much lower temperature than gan ; zno can emits light with shorter wavelength than blue light emission from gan ; zno has higher excitonic binding energy ( ~ 60mev for zno, 25mev for gan ), which promises strong photoluminescence from bound excitonic emissions at room temperature ; meanwhile, homogeneous bulk zno is available
和gan相比, zno薄膜具有生長溫度低,激子復合能高( zno : 60mev , gan : 21 25mev ) ,受激輻射閾值較低,能量轉換效率很高等優點。有可能實現室溫下較強的紫外受激發射,制備出性能較好的探測器、發光二極體和激光二極體等光電子器件。分享友人