QC 351 A7 no. 39 / Optical systems known as "null correctors" are often required to test certain aspheric optical surfaces. This report classifies these systems on the basis of their first -order geometry and analyzes the merits of each type. The behavior of optical aberrations, especially spherical aberration, in these systems is examined in the context of computer optimization techniques, particular attention being given to some design problems unique to null correcting systems. Orthonormal concepts are applied to the problem of reducing spherical aberration in null correctors. It is shown that exceedingly simple merit functions may be constructed to streamline the optimization process. These merit functions are composed of simple linear sums of the angular spherical aberration coefficients B1, B3, B5, and B7. Thus, minimizing the following sums will improve nearly diffraction - limited systems: ( - 13 B1 + 1 B3 - g' B5 - B7) , ( 4.131 - B3 - B5) , ( - 2B1 - B3) , and ( - B1) /1-5- 3/7 3 or ( 120 B3 + 960 B5 + 840 B7 ) , ( 840 B5 + 2520 B7) , and ( 840 B7) Non -diffraction - limited systems may be optimized by minimizing the sums ( 6 B3 + 5 B5 + 5 B7) , ( p B5 + 3 B7) , and ( 1 0 B7) To demonstrate the effectiveness of the techniques discussed, the process of designing a specific null correcting system is followed in detail.

by Kwok Chi Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references. / Abstract / Acknowledgements / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Basic Concepts of Lasers and Simple Survey of Laser Theories --- p.4 / Chapter 2.1 --- Introduction --- p.4 / Chapter 2.1.1 --- Basic Structure of a Laser --- p.4 / Chapter 2.1.2 --- "Concepts of "" Mode"" arid "" Mode-Locking""" --- p.6 / Chapter 2.2 --- Brief Review of Laser Theories --- p.9 / Chapter 2.3 --- Other Simple Models --- p.12 / Chapter 2.4 --- Review of the Maxwell-Bloch Equations --- p.17 / Chapter 2.4.1 --- Derivation of Maxwell-Bloch Equations --- p.17 / Chapter 2.4.2 --- Continuous-Wave Operation --- p.23 / Chapter 2.4.3 --- Mean-Field Approximation and Lorenz-Haken Instability --- p.24 / Chapter 2.4.4 --- Adiabatic Elimination of Fast Variables --- p.26 / Chapter 2.4.5 --- Thin-Sheet-Gain Approximation for Multimode Lasers --- p.30 / Chapter 2.4.6 --- Self-Mode-Locking Predicted by Using Maxwell-Bloch Equations --- p.33 / Chapter 2.4.7 --- Hysteresis Phenomena in Switching the Cavity Detuning --- p.35 / Chapter 3. --- "Moving-Mirror ""Mode-Locking""" --- p.41 / Chapter 3.1 --- Conventional Laser Mode-Locking --- p.41 / Chapter 3.1.1 --- Preliminaries： What is Mode-Locking (Conventional) ？ --- p.41 / Chapter 3.1.2 --- Active Mode-Locking and Passive Mode-Locking --- p.43 / Chapter 3.1.3 --- Spectra of Conventional Mode-Locked Lasers --- p.49 / Chapter 3.2 --- Moving-Mirror Mode-Locking --- p.50 / Chapter 3.2.1 --- Historical Notes --- p.50 / Chapter 3.2.2 --- Previously Proposed Explanations --- p.54 / Chapter 3.3 --- MMML Mechanism: our Proposal --- p.59 / Chapter 3.3.1 --- Relation between MMML Lasers and FSFC Lasers --- p.60 / Chapter 3.3.2 --- Concept of Moving Modes --- p.62 / Chapter 3.3.3 --- How are the Moving Modes Locked ？ --- p.64 / Chapter 3.4 --- Numerical Simulations ´ؤ Method and Results --- p.68 / Chapter 3.4.1 --- Description of Our Numerical Model --- p.68 / Chapter 3.4.2 --- Tests on the Simulation Method --- p.71 / Chapter 3.4.3 --- Ultrashort Pulses Generation of a MMML Laser --- p.73 / Chapter 3.4.4 --- Modulation of the Pulses --- p.74 / Chapter 3.4.5 --- Broadband or Discrete Spectra ？ --- p.75 / Chapter 3.4.6 --- Different Operation Regimes in MMML Lasers --- p.79 / Chapter 3.4.7 --- Why Period-T/2 Pulses --- p.84 / Chapter 3.4.8 --- Auto-Correlation Function of the Electric Field --- p.86 / Chapter 3.4.9 --- FSFC Laser with Injection Signal --- p.87 / Chapter 3.4.10 --- MMML in Class C Laser: d = 1.0 --- p.88 / Chapter 3.4.11 --- Exciting the Relaxation Oscillation Resonance --- p.89 / Chapter 4. --- Discussion and Conclusion --- p.92 / Chapter 4.1 --- Limitation of (Conventional) Thin-Sheet-Gain Approximation --- p.92 / Chapter 4.1.1 --- Problem with the Conventional Thin -Sheet-Gain Approximation --- p.92 / Chapter 4.1.2 --- Modified Thin-Sheet-Gain Approximation --- p.93 / Chapter 4.2 --- Concluding Remarks; Possibilities of Further Research --- p.97 / References and Notes / Appendix: Source Codes of the Fortran Program

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2016-09-16T18:27:23Z No. of bitstreams: 1 Cícera Vanessa Maia.pdf: 2746848 bytes, checksum: 656dfad8f5f006c37ac062a59a97290e (MD5) / Made available in DSpace on 2016-09-16T18:27:23Z (GMT). No. of bitstreams: 1 Cícera Vanessa Maia.pdf: 2746848 bytes, checksum: 656dfad8f5f006c37ac062a59a97290e (MD5) Previous issue date: 2016-05-02 / The research initiated when observing a phenomenon in the classroom and when searching for understanding this processes that was taking place during classes of Performing Arts, through experiences of students in front of the mirrors. Therefore, there was the need to find scholars who could support such knowledge. It was then that the phenomenological method, from Goethe, expanded research offering students freedom in the process and intensifying the observation of the phenomena. Firstly, throughout a period of fifteen years the role of the mirror in the Theatre Group of Centro Federal de Educação Tecnológica (CEFET-MG) is reported by analyzing aspects of the context of each scene and the tool used by the group of actors. Supportive sources of knowledge and theatrical techniques that established the trajectory of the group during this first part, were theater’s authors, such as Boal, Brechet, Koudela, Spolin. Other authors being, Sartre, Ponty, Ostrower were examined to assist in the understanding of subjective interpretation processes, as well as to describe the object of research, to deepen in the concept of image and in the action of the students when seeing themselves in mirrors in the room. During the experiment, the adaptations to the process were taken note and the mirror tool described throughout the steps of formatting the class method. To this point, the methodology chosen was ethnography based on the autobiographical narrative that can take the phenomenon and its processes to an empirical research. Duvignaud, Morin, are authors who have made the languages of dialogue processes and phenomena. In phenomenology, the seven steps are very clear principles that have been experienced, first, by the researcher and then systematized into steps of enjoyment between students and mirrors, and, only later, to systematize the phases of method. The author that supported this study was Bach Jr., when clearly presenting, the phases of Goethe's phenomenological. The research, after presenting the method and its applicability proven in the past ten years, presents a format that might be a menu for the discipline of Performing Arts / A pesquisa partiu dos fenômenos observados em sala de aula e na busca do entendimento dos processos que ocorriam nas aulas de Artes Cênicas a partir das vivências dos alunos frente aos espelhos. Buscamos teorias que pudessem ampliar meus conhecimentos. Foi então que o método Fenomenológico, de Goethe, amparou a intensificação na observação da pesquisadora aos fenômenos. Primeiramente, durante quinze anos a função do espelho no Grupo de Teatro do Centro Federal de Educação Tecnológica (CEFET-MG), são analisados os aspectos do contexto da cena como a ferramenta utilizada pelos atores do grupo. Nesse percurso, os autores de teatro Boal, Brecht, Koudela e Spolin, como fontes de conhecimento e técnicas teatrais, estabeleceram a trajetória do grupo. Na segunda parte, a Fenomenologia e sua Epistemologia foram incorporadas como base para a compreensão dos passos, na sistematização do processo observado e a intuição como experimentação da pesquisadora. Outros autores, Ricoeu, Sartre, Ponty e Ostrower, foram visitados para auxiliar a compreensão da subjetividade, interpretar os processos, descrever o objeto da pesquisa e aprofundar o conceito de imagem, na ação dos alunos quando eles se veem nos espelhos na sala. Na ação do experimento, as adaptações ao processo iam sendo aferidas e a ferramenta espelho, descrita nas etapas das aulas, formatando um método. A metodologia escolhida foi a etnografia que, junto a narrativa autobiográfica pode descrever os fenômenos e seus processos e sub processos em uma pesquisa empírica. As análises de dados vão sendo apresentadas no estudo, em paralelo as adaptações do processo fenomenológico, até chegar à sistematização de sete passos, etapas do método quando da utilização dos espelhos. Duvignaud e Morin são autores que fizeram o diálogo das linguagens dos processos e os fenômenos. Na fenomenologia, as sete etapas têm princípios bem claros que foram vivenciados, primeiramente, pela pesquisadora para depois sistematizar as etapas de fruição dos alunos com os espelhos e, posteriormente, as fases do método. O autor que sustentou esse estudo foi Bach Jr., quando apresenta, de forma clara, as fases da fenomenológica de Goethe. A pesquisa, após apresentar o método e sua aplicabilidade conferida nestes dez anos, apresenta um formato que possa vir a ser uma ementa de disciplina em Artes Cênicas

This work explores the interactive use of mirrored and reflective materials in the context of fashion. It draws parallels between the way in which it has been used in architecture in comparison to fashion and seeks a way to make a fair translation between the two mediums. The motive behind this work lies in the curiosity to explore reflective mirror materials in clothing beyond simply as shiny surface materials and aims instead to explore its illusive properties when combined with archetypical pattern prints. This to explore the potential aesthetic expressions it could bring to the fashion field. Using the theoretical approach of convergence, divergence, and transformation by Jones and methods by Thornquist that was slightly modified and reworked to fit the context of this project. Investigations with the reflective material were tested in different scales, both by draping with the material as is and by cutting and placing it in different ways in relation to the printed textile material. Derived from these experiments a new illusive material was created with special draping and shaping properties that came to define the collection as a whole.

A reflective Tiered Fresnel Zone Plate, herein called a Tiered Fresnel Mirror TFM, with a focal length on the order of a meter is studied for use as the mirror(s) in a Fabry-Perot interferometer type of laser. The relative phase transition within the individual zones (ideally smooth from zero to pi ) is stair-stepped or tiered in the longitudinal direction of the mirror. Within an individual zone the step height is constrained to a constant whereas the width of the tiers are monotonically decreased when traversing radially outward so that the overall profile follows the ideal smooth curve. The effectiveness of the number of tiers per zone, measured by the loss per pass or round-trip, varies from a Plane Mirror (zero tiers per zone) to a Spherical Mirror (an infinite number of zones per tier). The Fox and Li iterative method of determining the E-Field as the beam propagates back and forth is applied to an empty cavity resonator to determine the diffraction loss. A computer program is written to investigate the diffraction loss of various mirror configurations. The performance of the TFM is found to be not as efficient as the Spherical Mirror (the number of tiers per zone is shown to be a major variable) but may be tolerable under applications of a moderately high gain laser medium. The Gaussian Fundamental mode is easier to maintain since the higher order modes have a higher loss per round trip. The manufacture of the TFM can be incorporated easily into an IC process thereby making the cost of the novel mirror relatively cheap when produced in quantities. A major cost variable is again the number of tiers per zone which is proportional to the number of processing steps. The TFM's performance with respect to the etch depth of the steps in the mirror's stair-stepped profile is simulated and found to be a very doable etch with the current plasma etch technology.

Whilst the underlying mechanisms of atmospheric turbulence are complex, the observed effects on imaging can be described in simpler terms. In this thesis, I address the effects seen as geometric distortions in anisoplanatic imaging and propose new digital restorations techniques that are real-time capable and predictive. The anisoplanatic problem arises in wide-field telescopic imaging and in new ventures of astronomy such as giant telescopes that process wide-field imagery. The methods proposed here, both digital and digital-optical hybrid, remove the position dependent distortions as a precursor to image analysis. Previous existing digital restoration techniques have used a prototype formed by averaging an image time sequence for image registration where valuable high frequencies information is lost due to the low-pass filtering effect of averaging. The proposed techniques are capable of using any arbitrary frame in the sequence as prototype, thus circumventing the low pass filtering effect and also allowing real-time implementation. Furthermore, these techniques are made predictive by the use of Kalman filtering. The predictive capabilities of these techniques open a new path to the combination of digital processing and adaptive optics that can result in hybrid systems. The key to adoption of hybrid systems is to reduce the complexity and expense of the optics and couple this with digital processing prediction. To this end I also propose a new type of inexpensive and fast piezoelectric deformable mirror based on the vibration modes of circular PVDF membranes that exhibit striking similarities to Zernike polynomials. It requires only two electrodes for actuation and a very simple driving signal generator, therefore constituting an inexpensive and viable alternative to existing deformable mirrors. With the emergence of multi-conjugate adaptive optics (MCAO) and multiobject adaptive optics (MOAO) in astronomy, and the more demanding correction required for long range surveillance imaging, this inexpensive deformable mirror and the real-time capable digital algorithms are promising building blocks for a hybrid solution to the anisoplanatic imaging problem.

Thesis--Université de Toulouse-Le Mirail, 1972. / Includes indexes. Includes bibliographical references (p. 700-733).

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This report examines the legacy of “mirrors for princes” literature, or advice literature for kings, in Iranian political thought, particularly in the modern period. While most scholars have studied ‘mirrors’ literature as a predominantly medieval phenomenon, this report argues that the genre and the ideals of kingship it articulates continued to flourish well into the modern period in Iran. Through an analysis of themes found both in the medieval Persian texts and the ‘mirrors’ composed in the Safavid and Qajar periods, this report demonstrates a remarkable continuity in the genre and in the ideology of kingship throughout centuries of dynastic and structural changes in Iran. Moreover, although the genre of ‘mirrors’ appears to have faded with the Qajar dynasty, this report shows how its ideology of kingship continued to influence the rhetoric of political legitimacy in the Pahlavi period. Muhammad Reza Shah in particular relied on the office of the king and his duties of executing justice and protecting Islam to justify both the necessity of the monarchy and his right to the throne. / text

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