Some Considerations on Optical Confinement and Free Carrier Confinement of Quantum Cascade
光的衍射英语作文
The Phenomenon of Light Diffraction: AScientific MarvelIn the vast and enigmatic realm of physics, the phenomenon of light diffraction stands as a testament tothe wave-like nature of light. This remarkable occurrence, which manifests when light waves encounter obstacles or apertures, is not only fascinating but also holds immense significance in various fields of science and technology.Diffraction, simply put, is the bending of light waves around the edges of an obstacle or through a small aperture. This bending is a direct consequence of the wave-likenature of light, which differs from the particle-like behavior exhibited by matter. When light waves encounter an obstacle, they spread out in a characteristic pattern known as a diffraction pattern. Similarly, when light passes through a small aperture, it spreads out in a similar pattern, known as a diffraction fringe.The diffraction pattern observed is unique to the shape and size of the obstacle or aperture. For instance, a circular obstacle will produce a characteristic ring-shaped diffraction pattern, while a rectangular aperture willproduce a pattern with distinct vertical and horizontal fringes. This characteristic behavior of light allows scientists to determine the shape and size of objects using diffraction techniques.The phenomenon of diffraction has found numerous applications in various fields of science and technology. In optics, diffraction gratings are used to split lightinto its constituent colors, a principle that underlies the operation of spectrometers and monochromators. In microscopy, diffraction-limited imaging techniques are employed to achieve higher resolution images, enabling scientists to observe finer details than ever before.Diffraction also plays a crucial role in quantum mechanics, where it is used to probe the atomic and molecular structure of matter. Techniques like electron diffraction and neutron diffraction provide insights into the internal structure of crystals and molecules,揭示物质内部的原子排列和相互作用。
光学减反射英语
光学减反射英语Optical anti-reflective coatings are a marvel of modern technology, designed to minimize the reflection of light and enhance the transmission through glass or plastic surfaces.These coatings are particularly crucial in applications such as eyeglasses, where they reduce glare and provide a clearer view, improving the wearer's visual experience and comfort.In the realm of photography, anti-reflective coatings on lenses are indispensable. They help in capturing true colorsby allowing more light to pass through, thus reducing the distortions caused by reflections.The science behind these coatings involves theinteraction of light waves with the material's surface. By carefully engineering the thickness and composition of the coating, reflections can be significantly reduced.Moreover, anti-reflective coatings are not just limitedto visual clarity; they also play a role in energy efficiency. For instance, in solar panels, these coatings can increasethe efficiency by allowing more sunlight to be absorbed.The advancement in nanotechnology has further refined the process of creating these coatings, making them thinner and more effective. This progress has opened up new possibilitiesin various industries, from automotive to aerospace.In conclusion, optical anti-reflective coatings are an essential innovation that has transformed the way we interact with light, improving both functionality and aesthetics across a wide array of applications.。
通用学术英语写作_中国政法大学中国大学mooc课后章节答案期末考试题库2023年
通用学术英语写作_中国政法大学中国大学mooc课后章节答案期末考试题库2023年1. 5.First of all, watching TV has the value of sheer relaxation. Watchingtelevision can be soothing and restful after an eight-hour day of pressure,challenges, or concentration. After working hard all day, people look forward to a new episode of a favorite show or yet another showing of Casablanca or Sleepless in Seattle. 该段的衔接手段主要是_____与______。
参考答案:近义词（话题近义词 TV-television-show-showing; 主题近义词relaxation-soothing-restful）、上下义词(TV--Casablanca or Sleepless in Seattle)2. 2.We hear a lot about the negative effects of television on the viewer.Obviously, television can be harmful if it is watched constantly to theexclusion of other activities. It would be just as harmful to listen to DCs allthe time or to eat constantly. However, when television is watched inmoderation, it is extremely valuable, as it provides relaxation, entertainment, and education. 该段两大内容是________与_________。
Modern Application of mooc课后章节答案期末考试题库2023年
Modern Application of Optoelectronic Technology_南京邮电大学中国大学mooc课后章节答案期末考试题库2023年1.Reconstructive spectrometer is based on compressive sensing theory.参考答案:正确2.Photoconductive detector gain depends on the difference of electron andhole drift speed参考答案:正确3.As tandem structure can increase solar cell efficiency, so we can add as manycells as possible to increase the overall absorption and energy conversionefficiency.参考答案:错误4.The solar cell performance can be degraded by参考答案:Series resistance_Defects in semiconductors_Shunt resistance5.The optical transition in silicon devices is usually indirect参考答案:正确6.Write the bandgap (300k) of silicon _______ eV.参考答案:1.117.The commercial solar cell panels are still dominated by silicon photovoltaics.参考答案:正确D means __________________________参考答案:charge coupled device9._____________________are the study and application of _________________ devices andsystems that source, detect and control ______________.参考答案:Optoelectronics, electronic, photon##%_YZPRLFH_%##Optoelectronics, electronic, light10.Which of the following factors affect the LED output spectrum？参考答案:Operation temperature_Semiconductor bandgap_Dopingconcentration_Applied voltage/current11.Conventional spectrometers used in laboratories are参考答案:Based on dispersive optics_High resolution12.Some typical research results show that graphene hybrid photodetectors can参考答案:Cover a wide detection bandwidth from UV to MIR._Have highresponsivity_Use both planar and vertical heterostructures._Have high detectivity13.The equation to express photoelastic effect is【图片】, which means therefractive index changes with strain参考答案:正确14.What are the four typical layers of optical fibers?____________,___________,____________,_____________.参考答案:core, cladding, protective polymeric coating, buffer tube15.Second harmonic generation happens when an intense light beam offrequency ω passing through an appropriate crystal (e.g., quartz) generates a light beam of half the frequency, 1/2ω参考答案:错误16.The two regimes in acousto-optic modulators are Raman-Nath regimeand___________参考答案:Bragg regime17.Optically anisotropic crystals are called __________ because an incident lightbeam may be doubly refracted. There is also a special direction in abirefringent crystal, called the optic axis.参考答案:birefringent18._____________ is the rotation of the plane of polarization by a substance参考答案:optical activity19.What efficiency is typical of a commercial PERC solar panel?参考答案:20%20.The advantages of perovskite materials include参考答案:High quantum yields_Low-cost_High quantum yields21.Typical optoelectronic process includes参考答案:Light transmission_Light modulation_Light detection_Light generation22.The two operation principles of photonic crystal fibers are ___________________and _____________________.参考答案:total internal reflection, photonic bandgap23.The propagation modes in waveguide can be classified in terms of____________________(TE) mode and ____________________(TM) mode?参考答案:transverse electric field, transverse magnetic field24.Kerr effect can be used to induce birefringence参考答案:正确25.The lattice constant of AlGaAs alloy follows nonlinear mixing rule参考答案:错误26.Which of the following is not a challenge for 2D semiconductor technology?参考答案:Materials choice27.In the space charge region, a high doping concentration results a shortdepletion width参考答案:正确28.CMOS means __________________________参考答案:complementary metal oxide semiconductor29.Photodetectors convert ___________________ to an electrical signal such asa____________________.参考答案:light, voltage or current##%_YZPRLFH_%##photon, voltage or current。
How to Tilt and Decenter a Sequential Optical Component
How to Tilt and Decenter a Sequential Optical ComponentThe Coordinate Break SurfaceIn the sequential ray-tracing mode of ZEMAX, the order in which surfaces are entered matters enormously. The order specified in the Lens Data Editor (LDE) gives the exact order in which light interacts with the component surfaces of the optical system.One surface is therefore placed a thickness (a distance along the local z-axis) away from the previous surface. This is known as a local coordinate system, because the location of a surface is specified in terms of the previous surface.A Coordinate Break (CB) surface allows you to specify the location of the next surface as being shifted in x and y, and tilted (rotated) in x, y and z as well as simply shifted in z. The Coordinate Break is a dummy surface: that is, it has no refractive or reflective power and cannot bend rays. Its sole purpose is to define a new coordinate system in terms of the current one. Using such a surface allows you to separate the geometric location of a surface fromits optical properties.In this article we will show how to tilt and decenter an optical component while leaving the position of all other components unchanged. After explaining precisely how to do this, we will show a tool that simplifies the whole process, but it is important you understand how the tool works, and so a careful reading of the whole article is advised. In the attached zip file, you will find a file, starting point.zip, which shows three glass windows, the central one of which is two optical materials glued together.Eack of the windows has rectangular apertures applied (double-click on any surface and look at the Aperture tab to verify). Any ray that lands outside the aperture on a surface will be terminated.In the above screenshot, positive z is in the left-to-right direction, positive y is going up the page and positive x is going into the page. This is a right-handed coordinate system, in which z is on your index finger, y on your thumb and x on your middle finger, and your index finger is pointing from left to right, as shown by the coordinate axes in the bottom left-hand corner or the 3D Layout.Our task in this article is to tilt and center the central window while leaving the other two windows in exactly their original locations. How will we know when we have achieved this? ZEMAX has a report which is vital whenever you are working on a tilted or decentered system.Open Reports > Prescription Report, and look at the section headed Global Vertex:The Global Vertex report lists the position and orientation of the vertex of each surface with respect to the Global Coordinate Reference Surface (GCRS). In this design, surface 1 is the GCRS, but any surface may be selected either from the Type tab of the Surface Properties or from the Misc tab of the System Properties dialog boxes.From the Global Vertex report it can be seen that all surfaces are on-axis with respect to the GCRS, as the rotation matrix is a unit matrix for all surfaces and the {x,y} coordinates of each surface is zero. Surface 7 (the front surface of window 3) has {x, y, z} coordinates {0,0,33} with respect to surface 1, the GCRS.The Coordinate Break (CB) surface allows you to specify a decentration in x, decentration in y, tilt in {x, y, z} as well as shift in z (thickness) that affects all subsequent surfaces. It also has an order flag, the purpose of which we will discuss later.Our first task is to decenter the middle window, without disturbing the location of any other surfaces.Decentering a ComponentIn order to decenter the middle window, click anywhere on surface 4 (it has the comment Front Window2) and press the INSERT key on the keyboard. A new surface will be inserted, and all surfaces from the old surface 4 onwards will have been renumbered (so that surface 5 now has the comment Front Window2).Now double-click on the new surface 4 and set it to a Coordinate Break surface:Then scroll along to the y-decenter and enter a value of -5 mm. The Layout Plot and Prescription Report show the consequence. All surfaces from the Coodinate Break onwards are decentered by -5 mm.To demonstrate this, click on Surface 8 (the front of window 3), press INSERT again and make the new surface a CB. Make the thickness of this surface 10 mm, and make the thickness of surface 7 zero, so that the second CB is colocated with the back of the middle window. Give this CB a decenter in y of +5. You should now have the following (open intermediate step.zmx from the zip if you got lost). {Note that because of the rectangular apertures on the surfaces, rays that miss the middle window are terminated. This is an essential part of the sequential model. If you wish to model a system in which rays that miss the middle window carry on to hit the third window, you must usenon-sequential ray-tracing.}The restoring CB restores the original coordinate axes so that subsequent surfaces are back in their original positions.Setting the values of the restoring coordinate break surface by hand is not good practice, as its easy to forget that the second CB needs to be adjusted whenever the first one is. However, ZEMAX makes it easy to automate: just double-click on the y-decenter of the second CB and choose a Pick-Up solve to lock the value to the first CB, as follows:Do this with the decentration in x, and for the tilt parameters also, but leave the order flag = 0 f or both CBs at this time. (This is an error, but we will see why in the next page).You should be able to set any value of decenter in x and y, and ZEMAX will restore the original coordinate system at the second CB. If you got lost, open intermediate step2.zmx from the attached zip archive. We will now move onto tilts.Tilting a componentReset all parameters on the first CB to zero. The parameters of the second CB should automatically set themselves to zero because of the pick-up solves. Then set the tilt-x of the first CB to 20 degrees. At first glance, this looks like all we need to do, but when the Global Vertex report is looked at carefully, it is obvious that something is wrong.A y-decentration of 0.68 mm has been introduced by the x-tilt. This is because the second coordinate break is implemented some distance along z of the new, x-tilted coordinate system. In order that we introduce a pure tilt with no decentration, there must be zero z-shift between the two CB surfaces. This is achieved by a dummy propagation before the second CB.Insert a dummy surface immediately after the second coordinate break. The second CB currently has a thickness of 10. Set this to 0, and make the thickness of the new dummy surface 10. Now the z-shift between the two CBs is a total of 2 mm, so make the thickness of the surface immediately before the second CB -2, and make the thickness of the second CB +2. This dummy propagation places the two CBs at the same point in space, and so the untilting operation introduces no decentration.The dummy surface has no optical effect because we trace -2 mm in air followed by +2 mm in air, so no rays are bent, no optical path length is added. The dummy surface may be hidden using the "Do Not Draw This Surface" and "Skip Rays From this Surface" controls on the Draw tab of the Surface Properties.However, the way in which the dummy propagation thickness has been set is unsatisfactory. What would happen if the thickness of one of the glass surfaces changed, either by hand or during optimization? The second CB would no longer be correctly placed. The key thing is that the second CB must be at the same position as the first, and ZEMAX has a simple, powerful way to ensure that this condition is always met: a position solve.A position solve sets the surface after it to have a specified distance from another surface. Double-click on the thickness of the surface immediately before the second CB (this currently has a thickness of -2), and in the solve dialog box choose:Note that the position solve lets us go back through any number of surfaces until we get to the first coordinate break Then put a pick-up solve on the thickness of the second CB, that picks up the value of the position solve and multiplies it by -1. Now change the thickness of the glass surfaces between the two CB surfaces. No matter what thickness you enter, the second CB is always exactly co-located with the first, and so can undo it perfectly.Finally, notice one more thing. Set a y-tilt of 30 degrees and an x-tilt of 10 degrees. Note that the second CB no longer undoes the first one perfectly. This is because the order of the tilts matters. If we tilt about x, and then tilt about y in this new tilted position, then we must untilt about y and then untilt about x in order to restore the original coordinate system. This is what the Order flag is for. If the Order flag is zero, the CB surface executes such that decenters are done first, and then tilts in order. If the Order flag is non-zero, the CB executes in reverse order. This meas that a single CB can unstrip any compoundtilt/decenter introduced by another other CB that it is co-located with.The final system is included as final system.zmx in the attached ZIP archive. Here is the system, with any number of tilts and decenters, showing that the position of the third window is unaffected . Note the dummy surface has been hidden.But isn't there any easier way to do all this? There isThe Tilt/Decenter Elements ToolThis is the easy way to tilt/decenter an optical element. Re-open starting point.zmx, and then click on Tool > Miscellaneous > Tilt/Decenter Elements, and enter whatever tilt/decentration data you want, for example:Note that this tool does everything we did by hand! Using the tool is highly recommended as the standard technique by which you should tilt or decenter optical components in your system.Summary and ReferencesIn summary, in order to tilt/decenter an optical element in a sequential optical system:Two coordinate break surfaces are usually required, one to perform the compound tilt/decenter and the other to restore the original axis∙The two CB surfaces must be co-located, which is done most easily with a position solve∙The decenters and tilts of the second CB must be the exact reverse of the first CB. This is most easily achieved with pick-up solves∙The order in which decenters and tilts are applied by the second CB must be the reverse of that used by the first. The Order flag is used to achieve this∙The Tilt/Decenter Element Tool is the easiest way to achieve all this in one step, and is strongly recommended.∙Check the results with the Global Vertex section of the Prescription Report to ensure surfaces are placed where you expect them to be.。
微波光电子学
微波光电子学研究光波与微波的相互作用，
主要包括光的微波调制，外差光生微波源， 微波信号的探测，微波器件的光学控制等 领域的机理和技术。 微波光电子学的主要应用领域包括光信息 处理，微波的光载传输，相控阵天线波束 光学实时延迟控制及波束合成。
• 光对微波信号产生、放大与交换的调
控作用，主要是利用光对微波半导体
器件有源层中载流子浓度和运动的激
发与控制；
• 微波对光传输、折射偏振及信号传递
的调ቤተ መጻሕፍቲ ባይዱ作用则利用导光媒质的极化与
载流子分布受微波场变化而导致光导
率、折射与偏振特性的改变。
微波光电子学早期工作 1. Optical sources capable of fast modulation; 2. Suitable transmission media; 3. Fast optical detectors;
Faster response requires high p： • reducing the photon lifetime p short optical cavity, reduced facet reflectivity • increasing the differential gain g0 reduced dimensionality • increasing the photon densities S0 small cavity volumes or short and narrow optical waveguides
3. Fast optical detectors For detection, fast depletion and
avalanche detectors were developed at
法学翻译题目
法律名称格式：名称of主体on事宜办法：measure(办法措施)procedure（正式法律）规定：regulation; rule; provision（正式法条）管理：administration administrative（西方纯管理）executive（中国行政管理）通则；总则：general provisions；general principle法规标题：title发文字号：document number（法）;issue number（出版）时效status颁布日期：promulgation date（法）;issue date（出版）实施日期：effective date; implementation date失效日期：repeal date; expiration date颁布单位：issuing organizationconvention公约Geneva Conventions日内瓦公约implementing rules实施细则The Agreement on Safeguard保障措施协议working party工作组shall be在法律文本中常作must be“凡是”，法律文本中只用shall不用should court of appeals上诉法院enforcement power执法力量Vendor供应商distributor经销商retailer零售商SEPTA宾夕法尼亚州东南地区交通局Insure承保be liable for对...承担责任Waiver放弃...（法律用语）Subrogation Extension代位求偿权damages损坏赔偿金Premium保险费Policy保单Notwithstanding...it is agreed that尽管......兹经双方同意Blackstonian conception of property布莱克斯通主义（个人绝对财产观）takings law收入法Torts侵权责任法common-law tradition英美法系制定法：statute（英）jurists法学家“silent erosion”“沉默的侵蚀”Guantanamo Bay关塔那摩湾（美国用于关押外国战俘）Boumediene各州Justice大法官treason叛国罪restrictive interpretation限制性解释in dubio mitius国际公法中“如有疑义从轻解释”The Permanent Court of International Justice (PCIJ)国际常设法院VCLT (Vienna Convention on the Law of Treaties)《维也纳条约法公约》ICJ (International Court of Justice)海牙国际法庭Policy保单Term条款，还有clauseLiability免责Injunction禁令Attorney General司法部长；检察长Piracy盗版Anonymity匿名Strip the citizenship取消国籍Censorship审查制度Decriminalization合法化Hereinafter referred to as...以下简称......诉讼：criminal charge(刑)sue(民)arbitration仲裁mediation调解public institute事业单位personnel人事Pursuant to law依法1 （519 words）Appreciating the role of property in promoting public welfare necessitates rejecting the Blackstonian conception of property布莱克斯通主义（个人绝对财产观）because market failures and the physical characteristics of the resources at stake often require curtailing an owner’s dominion so that ownership can properly serve the public interest. A similar lesson emerges from the robust economic analysis of takings law收入法. This literature indeed shows that compensation is at times required to prevent risk-averse landowners from under-investing in their property and to create a budgetary effect that, assuming public officials are accountable for budget management, forces governments to internalize the costs of their planning decisions. These considerations are particularly pertinent to private homeowners, who are not professional investors and who have purchased a small parcel of land with their life savings, as well as to members of a marginal group with little political clout. But providing private landowners and public officials with proper incentives also implies that, in other cases, full compensation should not be granted. Where a piece of land is owned as part of a diversified investment portfolio, full compensation may lead to inefficient overinvestment, while the possibility of an uncompensated investment is likely to lead to an efficient adjustment of the landowner’s investment decisions commensurate with the risk that the land will be put to public use. Similarly, landowners who are members of powerful and organized groups can use non-legal means to force public officials to weigh their grievances properly. An indiscriminate regime of full compensation may therefore distort the officials’incentives by systematically encouraging them to impose the burden on the non-organized public or on marginal groups, even when the best planning choice would be to place the burden on powerful or organized groups. The absolutist conception of property and the strict proportionality takings regime are also anathema to the most attractive conceptions of membership and citizenship, which insist on integrating social responsibility into our understanding of ownership. The absolutist conception of property expresses andreinforces an alienated culture, which “underplays the significance of belonging to a community, [and] perceives our membership therein in purely instrumental terms.”In other words, this approach “defines our obligations qua citizens and qua community members as ‘exchanges for monetizable gains,’ . . . [and] thus commodifies both our citizenship and our membership in local communities.”To be sure, the impersonality of market relations is not inherently wrong; quite the contrary, by facilitating dealings “on an explicit, quid pro quo basis,”the market defines an important “sphere of freedom from personal ties and obligations.” A responsible conception of property can and should appreciate these virtues of the market norms. But it should still avoid allowing these norms to override those of the other spheres of society. Property relations participate in the constitution of some of our most cooperative human interactions. Numerous property rules prescribe the rights and obligations of spouses, partners, co-owners, neighbors, and members of local communities. Imposing the competitive norms of the market on these divergent spheres and rejecting the social responsibility of ownership that is part of these ongoing mutual relationships of give and take, would effectively erase these spheres of human interaction.在改善公共福利的过程中给资产增值往往与布莱克斯通主义（个人绝对财产观）的观点相矛盾，因为市场失灵和关键资源的特性经常会要求缩小所有者的独享权，这样所有权才能以适当的方式为公共利益服务。
光学效应 英语作文
光学效应英语作文The Optical Effect。
Introduction。
The optical effect is a fascinating phenomenon that occurs when light interacts with various materials, resulting in the manipulation of light waves and the creation of stunning visual effects. From the iridescence of a soap bubble to the shimmering colors of a peacock's feathers, the optical effect is all around us, and its beauty and complexity never fail to captivate our imagination.Explanation of the Optical Effect。
The optical effect is a result of the interaction between light and matter. When light waves encounter a material, they can be reflected, refracted, or diffracted, leading to a variety of visual effects. One of the mostcommon optical effects is iridescence, which occurs whenlight waves are scattered by the microstructures on the surface of a material, creating a rainbow-like display of colors. Another well-known optical effect is the shimmering of a mirage, which is caused by the refraction of light asit passes through layers of air with different temperatures. Applications of the Optical Effect。