Optical and optomechanical design of multiscale gigapixel camera system

4.1 Definition of a Thin Lens A thin lens is a theoretical lens whose thickness is assumed to be zero and, therefore, negligible during thin-lens calculations. The thin lens is a design tool used to simulate a real lens during the preliminary stages of optical system design and analysis. The concept is particularly valuable because it enables the optical engineer to quickly establish many basic characteristics of a lens or optical system design. By assuming a lens form where the thickness is zero, the formulas used to calculate object and image relationships are greatly simplified. The drawback to the thin-lens approach is that it is not possible to determine image quality without including actual lens thickness (and other lens data) in the calculations. As a result, while it is possible to establish many valuable facts about an optical system by the application of thin-lens theory and formulas, the ultimate quality of the final image can, at best, only be estimated. 4.2 Properties of a Thin Lens Figure 4.1 is an illustration of a positive thin lens. Any lens system analysis must start with several known factors that will generally be provided by the end user, i.e., the customer. From these given starting factors it will be possible, using thin-lens theory and formulas, to generate the missing information required to completely describe the final lens system. In the case shown in Fig. 4.1, for example, it is given that the system detector (image size) will be 25 mm in diameter and that the full field of view of the lens will be 10 deg. Other system considerations dealing with detector sensitivity - thus required image brightness - dictate that a lens speed (f/#) of f/2.0 will be required. Since we know the image size and the field of view, applying the formulas shown in Fig. 4.1, we can calculate the effective focal length (EFL) of the lens. The image size dimension used for this calculation is measured from the optical axis and is designated as y1. In this case, the maximum value for y1 is 12.5 mm.

In this paper, we describe the optical, optomechanical, and optoelectronic design of a multistage optical backplane demonstration system. In addition, operational testing and performance is discussed.

This thesis examines the contribution made by the U.S. print media to the development of Nelson Mandela's public persona. The period studied is from 1985 to June, 1990. This thesis explores the following questions: 1) How did the public persona of Nelson Mandela evolve in the dominant U.S. print media; 2) How do these stories, in content and form, serve to establish Nelson Mandela as a public hero; 3) What cultural myths structure the news stories of Nelson Mandela that serve as the interpretative framework for public belief and action? Data for analysis were drawn from The New York Times, The Los Angeles Times, and The Wall Street Journal. Each newspaper has a daily circulation of over 1 million. It was found that during the period studied, the development of Mandela's public persona occurred in two distinct phases: 1985 to mid-1989 and late 1989 to June, 1990. Analysis reveals that the media relied on narrative form to create an image of Mandela which invites the reader to accept, believe in, and support Mandela and his cause. During these phases the media established Nelson Mandela as a hero and celebrity for their reader audience via a number of rhetorical practices. These include: the introduction of Mandela as a legend and hero among black South Africans; the practice of surrounding Mandela with mythical reference; establishing Mandela as an individual who subscribes to many traditional American values and; the serial reporting of pseudo-events. Implications of the study and suggestions for further research in the areas of textual analysis, policy analysis, and audience analysis are discussed.

This paper investigates the features of the US mass media approaches in creating the image of Hugo Chavez on the eve of the Venezuela 1998 Presidential Elections. The paper studies the historical context, which influenced the creation of Chavez's image. The socio-economic and political development of Venezuela in those days is analyzed. The key traits of Chavez’s image highlighted during the period under study, as well as the emotional background of the publications, are analyzed. Although both the domestic and foreign historiography has paid a most sufficient attention to the history of Venezuela, the biography and political activity of Hugo Chavez, his image as a presidential candidate in the 1998 Venezuela elections remains unexplored. This work aims to fill this gap. The paper systematically examines the materials of the three major US newspapers, namely, the “New York Times”, the “Wall Street Journal”, and the “Los Angeles Times”, published from July to December, 1998. The established methodologies of document analysis and quantitative content analysis are applied. The study leads to the conclusion that the USA mass media created a negative image of Hugo Chavez during the pre-election period, implementing understatements and a negative emotional background in their publications.

A prototype digital free-space photonic switching fabric is demonstrated. It consists of three cascaded 16 x 8 arrays of symmetric self-electro-optic-effect devices that are used as logic gates that implement part of a multistage interconnection network. We discuss architecture, device tolerancing, optical system design, and optomechanical design. This optical circuit is successfully configured as a fully operational array of 32 independent 2 x 2 nodes and operates at 100 kHz.

“OK boomer,” is a viral phrase used by members of Generation Z to dismiss the opinions of older adults. Given the rise in usage of and the varied reactions to the phrase, it is important to understand how, “OK boomer,” was portrayed in print media. To do so, news articles from the New York Times (NYT), Wall Street Journal (WSJ), and Washington Post (WaPo) that were printed during October 2019-February 2020 were collected. After organizing the data, a thematic analysis was completed, which showed that “OK boomer” was depicted as a form of demagogic discourse that reinforced age-based stereotypes. This portrayal relied on (1) an oversimplified definition of the phrase that was grounded in unidimensional stereotypes (2) the reinforcement of generational divides, and (3) the acceptance of ageist communicative behaviors in intergenerational interactions. Based on these findings, a series of theoretical and applied implications that problematize the use of the phrase and encourage productive intergenerational interactions are provided.

Articulation and Concordance: A Dialogue on Civil–Military Relations in Fiji

We present a novel method of increasing the focal depth of an optical system that can be used in a star tracker. The method is based on a special phase plate that is placed in the vicinity of the aperture stop of an optical system to produce the required spot size over a large focal depth. Phase retardation was applied to a lens system having a focal length of 30 mm, an F-number of 2, a working wavelength range of 0.5~0.75 μm and a view angle of 20 degrees. The performance of a lens having a suitable quartic phase was analyzed, and it was shown that the focal depth of such a lens system can be extended more than threefold as compared to a system having no phase plate.

This paper introduces and analyzes a theory for a paraxial design of a hybrid catadioptric optical system with variable focal length, which uses focus tunable optical components. Compared to the conventional zoom lens system, the proposed hybrid optical system can be designed with a smaller length and weight than a lens system of similar characteristics. The hybrid system does not need the movement of individual elements for zooming. All necessary relations for the calculation of the paraxial parameters and the third-order spherical aberration of the hybrid optical system are derived. The presented theory helps to find out the optical power distribution of individual optical elements of the whole hybrid zoom system considering the requirement on the spherical aberration of the system. In addition, the procedure for the calculation of basic design parameters of such an optical system is shown by examples.

The interface between optical design and fine-mechanical design is a creatively fertile stage in the design of an optical system. The optical designer learns `What the system is all about' and the fine-mechanical engineer is liberated creatively by finding out what the priorities are. On the other hand, optical tolerancing as a discipline, which is an attractive mix of optical physics at one end and hard-nosed mechanical pragmatism at the other, has a relatively fragmented literature. It is the purpose of this paper to (1) Point out some cultural contrasts between optical engineers, mechanical engineers and physicists in this context, (2) To present a new method of displaying the optical surface sensitivities so that one may identify datum surfaces in an intuitive way and (3) To summarize some useful formulae which provide a key to the mounting of optical components. Together these three aspects illustrate the scenery of this fertile terrain.

Matt Reeves' Cloverfield (2008) plays with vision and concealment, staging a game of hide and seek between audiences and the monster it promises to deliver. As a selfconscious entry in the monster movie genre, Cloverfield discloses its monstrous predator only in glimpses, through visual effects that allude to much, but reveal little. In this, the film departs from the usual cinematic treatments of monsters, which are typically displayed like curious zoological specimens: fantastic life forms whose features are to be studied, their destructive capabilities catalogued, and their weaknesses exploited. Our desire to experience the spectacle of these creatures is closely linked to our fascination with the novel visual effects technologies often tasked with animating them, creating interdependence between cinematic spectacle and cinematic technology - interdependence that Cloverfield uniquely complicates. We often think of spectacular cinematic illusions as stimulants that short-circuit our intellectual engagement by overwhelming our senses, particularly, by stressing the visual, but these illusions can deliver powerful semic pay loads even as they punctuate a storyline with shock and color. By exploring the limits of visualisation, special effects act as entry-points for spectators to consider the constructed nature of film (North 2008). Whatever sleights- of- hand fhey might use to cover their tracks, these special effects are self -reflexive devices that draw attention to visual deception, and bring into play an entire metanarrative about media technologies and illusion. This is most apparent in those films that foreground technical display (see, for instance how King Kong, in any of its versions, builds its story around a special effect that is also its pivotal character), but Cloverfield seems to complicate all of its spectacular opportunities, delaying any clear view of its central special effect. The monster at its heart is rarely glimpsed, usually obscured by buildings or misframed by the camera. The film's obstructed views extend to the whole fabric of the movie, including its pre- publicity campaign and its framing narrative. I want to outline some of the ways I think the film uses this aesthetic of opacity to construct a critique of film's apparent realism. The amateur aesthetic of Cloverfield is not just a trick to allow spectators to imagine that the depicted events are really happening before the camera. By simulating the impression that the monster is a chaotic agent not under the control of the filmmakers, not served up for viewing as a spectacular pay-off, Cloverfield feigns the appearance of documentary, where events should not seem to be unfolding in patterns pre- determined by genre or commercial expectation. Yet it is clearly a fantastic tale and therefore implies that, by convention, we associate documentary realism with specific formal techniques . . Cloverfield is a film about a monster attack on Manhattan, presented as the playback of a digital videotape shot by an amateur cameraman during the attack and later found in the city's rubble. A large creature of unknown origin emerges, presumably from the sea, and rampages downtown, leaving a tourist trail of destruction that takes in the Statue of Liberty, the Brooklyn Bridge and Central Park. The attack is shown from the point- of- view of a group of young adults who have been attending a party just before the city is thrown into a chaotic evacuation. The US military can be seen periodically, fighting a futile battle with the skyscraper-tall monster, which begins throwing off parasites that infect their victims with a lethal virus. One character defies the danger and attempts to cross the city to rescue the girl to whom he wants to declare his love, believing her to be in mortal danger. In this sense, Cloverfield follows a rather formulaic quest narrative, driven by a hero's race to rescue a damsel in distress from a high tower, avoiding the mortal threat posed by a fearsome beast. …

Minimizing the aberrations is the basic concern of all the optical system designers. For this purpose, a large amount of work has been carried out and plenty of literature can be found on the subject. Until the last twenty years, the large majority of the optical design was relat‐ ed to “static” optical systems, where several opto-mechanical parameters, such as refractive index, shape, curvatures, etc. are slowly time dependent. In these systems, simple mecha‐ nisms can be adopted to change the relative position of one or more optical elements (for example, the secondary mirror of many astronomical telescopes), or slightly modify their shape and curvature (as in some synchrotron beamlines, where some optical surfaces are mechanically bent) to compensate defocusing. In the last years, a new type of optical sys‐ tems, that we may call “dynamical”, have heavily occupied the interest of optical designers, opening the possibility of working also in situations where the system environment varies rather quickly with time, either in a controlled or not-controlled way. For this class of optical systems adaptive optics (AO) with a closed loop control system has to be implemented. The correction of dynamical systems was predicted by Babcock in the 1953 [1] and, then, the first prototypes were realized in the early 70s with the purpose of satellite surveillance and launching high power laser beams trough the atmosphere [2]. The most known scientific ap‐ plications of closed loop correction by means of AO is the acquisition of astronomical im‐ ages in ground-based telescopes [3] and in-vivo imaging of cone photoreceptor mosaic by AO enhanced Fundus Cameras [4]. In astronomy, to remove the so called “seeing effect”, the star light twinkling due to local dynamic variations of the atmospheric density in the air column above the telescope, it is necessary to have the real time knowledge of the wavefront of the observed object. This can be realized, for instance, by means of a Shack-Hartmann wavefront sensing device coupled to a dedicated fast algorithm which returns the mathe‐ matical description of the wavefront aberration, typically through a Zernike series decompo‐

716LANGUAGE, VOLUME 54, NUMBER 3 (1978) Part 5 need not concern us long. Three of the chapters—'Sociolinguistics', 'Language education', and 'Mass media and literacy in Ethiopia'—appeared in a previous collection (Bender et al. 1976); a fourth, containing both 'Languages of Northern Eritrea' and 'Languages of the Maji area' was omitted from that volume for reasons of economy. 'Hamer speech situations' alone is concerned solely with a non-Semitic language. It is interesting in its own right, but unrelated to the purely linguistic work in the rest of this volume. The great value of this book lies in the vast amount of material it contains, especially that which is new or virtually inaccessible. But why were previously published and easily accessible articles also included? If the intention was to provide representative coverage,then the obvious gaps(e.g. Somali)arereprehensible, and a real attempt should have been made to achieve some similarity and consistency in the presentation. Yet one should not be too critical. A 700-page volume on these languages is both unexpected and welcome. REFERENCES Bender, M. Lionel. 1971. The languages of Ethiopia: a new lexicostatistic classification and some problems of diffusion. AL 13.165-288. ------, et al. (eds.) 1976. Language in Ethiopia. London: Oxford University Press. Ehret, Christopher. 1971. Southern Nilotic history: linguistic approaches to the past. Evanston: Northwestern University Press. Greenberg, Joseph H. 1963. The Mogogodo: a forgotten Cushitic people. JAL 2.29^43. Heine, Bernd. 1975. Notes on the Yaaku language. Afrika und Übersee 58.27-61, 119-38. Moreno, M. M. 1940. Manuale di Sidamo. Milan: Mondadori. Palmer, F. R. 1970. Cushitic. Current trends in linguistics, 6: Linguistics in South West Asia and North Africa, ed. by T. A. Sebeok, 571-85. The Hague: Mouton. •-----. 1977. Review of Zaborski 1975. BSOAS 40.198-202. Sasse, Hans-Jürgen. 1973. Bemerkungen zum Language Survey of Ethiopia. ZDMG 123.117-28. Tucker, A. N. 1967. Fringe Cushitic: an experiment in typological comparison. BSOAS 30.655-80. Zaborski, Andrzej. 1975. Studies in Hamito-Semitic, 1: the verb in Cushitic. (Zeszyty Naukowe Uniwersytetu Jagiellonskiego, 397; Prace jçzykoznawcze, zeszyt 48.) Warszawa/Kraków : Uniwersytet Jagiellonski. [Received 21 July 1977.] Studies in the semantic structure of Hindi: synonymous nouns and adjectives with karanä. Volume 1. By Kali Charan Bahl. Delhi: Motilal Banarsidass, 1974. Pp. cxiv, 409. Rs. 100. Reviewed by Michael C. Shapiro, University of Washington The work here reviewed was clearly written with both lexicographic and theoretical goals in mind. It is intended, first of all, to serve as the initial installment of a reference dictionary of Hindi conjunct verbal constructions. This dictionary represents a considerable departure from Hindi lexicographic tradition, as it arranges items in ' synonymous ' groups and provides information on the semantic REVIEWS717 and syntactic properties of the forms listed. The work is also designed to provide a theoretical introduction to the study of Hindi conjunct verbs. This introduction consists of a critique of past approaches to the study of conjuncts, statements concerning Bahl's beliefs on the correct analysis of conjuncts, and expressions of his low opinion of the current state of Hindi lexicography. Hindi conjunct verbs are sequences consisting of either a nominal or adjectival element, followed immediately by a verb, frequently honä 'to be ' or kar(d)nä 'to do ', but often others.1 The nominal (N) or adjectival (A) constituent is sometimes linked by a postposition (PP) to other constituents of the sentence in which the conjunct is used. The substitution of one PP for another may be correlated with a semantic change. For example, the expression X ki carcä karnä ' to make mention of X', using the PP ki, can be distinguished from X se carcä karnä 'to mention to X', using se. Single N's or A's, as well as sequences of N -I- PP + A/N, can be followed by many different verbal elements. For example, N + par 'on, upon' + nazar 'vision, glance, line of sight' can occur with any of the verbs jänä, paRnä, dalnä, rahnä, dauRnä, rakhnä, jamänä, märnä, thaharnä, tiknä and honä; each sequence, according to B, has a distinct meaning. Many Hindi conjuncts are close paraphrases of non-conjunct expressions...

This paper argues that photography is best grasped not as a medium of visual communication, but as a manifest performance of the power to make visible. As such, photographic practices are central to the experience and demarcation of private/public boundaries in advanced media cultures. In the private domain, photography is both a ritualized domestic activity and provides conventional and definitive representations of the domestic. These functions are ostensibly opposed to photography's role in the public realm: the same visual technology becomes, in the mass media, both the index and agent of publicness itself, with the paparazzi−especially in the aftermath of Princess Diana's death−symbolizing the violation of the private. The paper explores the ways in which photographic performance at the public/private boundary dramatizes power relations through forms of social transparency, voyeurism and memoralization. It also asks whether momentary crises in the dominant scopic regime can provide the basis for alternative ‘uncanny’ visual practices that are tenable and empowering.

Surface quality of optical lenses is an important parameter to achieve optimal imaging quality. Surface imperfections such as scratches, pits, or digs which may be caused during manufacturing or handling induce light scattering and degrade the overall performance of the imaging system. For a lightweight lens, the pockets behind the lens will affect the defect judgment due to excellent optical transmittance. This article discusses the measurement flow of automatic optical inspection for large lenses, defect detection algorithm, and the practicality of application of this technique for inspection of large lenses. Surface defect detection module comprises of high dynamic range camera combined with telecentric imaging lens creating an imaging system with resolution of 2.7μm. Inspection of the whole surface before and after coating is carried out through concentric scanning and different illustrating angles. The images are captured with a 20% overlap between two consecutive images to ensure complete coverage of the whole surface. Image processing algorithms are applied to detect and classify any surface defects on the surface. Detection results consists of exact size, type, and location of the defects are analyzed by the system and summarized into an inspection report. Compared to classical manual inspection this system provides reproducible and objective detection results and allows users to perform revalidation after measurement is finished.