ميلياردها سال پيش انفجاربزرگ اتفاق افتاد،وجهان ما اغاز شد.علت انفجاربزرگ ، بزرگترين رازي است كه بشرهنوز نميداند،اين نظريه يكي از مهمترين موفقيت هاي علمي قرن بيستم است امروزه نمي توان جهان را بدون درك انفجار بزرگ شناخت ولي اين نظريه به نواحي كه فيزيك آن قابل فهم وآزمايش است محدود مي شودوتوضيحي براي نحوه ي تحول عالم در زمان هاي   ابتدايي تر وداغ تر ندارد. براي شناخت كيهان شناسي نوين بايد به اوايل قرن بيستم برگرديم،زماني كه انيشتين نظريه نسبيت عام خود را در سال1915 ميلادي منتشر كرد طبق اين نظريه بيان ميكند كه هندسه ي عالم با توزيع ماده ي درون عالم ،مشخص مي شود.در سال 1922 فريدمن جواب   معادلات كيهان شناسي انيشتين را برپايه ي يك عالم همگن وهمسانگرد بدست آوردكه به متريك FRW معروف شد.اين متريك نشان ميداد كه برخلاف تصور معمول آن زمان ،عالم درحال انبساط است. هابل در سال 1929بطور تجربي انبساط عالم توسط مشاهدات را تاييد كردو از ان پس متريك فريدمن به ابزار اصلي نظريه هاي كيهان شناسي تبديل شد.دراواخر دهه ي 1940،جرج گاموف وشاگردانش پيش بيني كردند كه جهان امروز بايد از تابش جسم سياه پر شده باشد ولي مشاهده ي تجربي اين پديده در سال 1965 انجام گرفت. در دهه ي 1970مشخص شداين تابش كه تابش ريزموج زمينه ي كيهانيCMB نام گرفت،به لحاظ توزيع فركانسي   داراي طيف تابش جسم سياه است.سرانجام جامعه ي علمي قانع شدند كه اين تابش باقي مانده اي از انفجار بزرگ است. بدين ترتيب مدل مهبانگ بعنوان مدل استانداردانفجار بزرگ پذيرفته شد. با كشف ويژگي همگني وهمسانگردي تابش زمينه ي كيهاني ،مشكلاتي چون تختي عالم،مشكل افق،مشكل تك قطبي ونيز منشا افت وخيزهاي اين تابش مطرح شدند كه كيهان شناسي استاندارد پاسخ قانع كننده اي براي اين مشكلات نداشت. كيهان شناسي تورمي اولين باربعنوان مدلي براي حل مشكلات نظريه ي استاندارد انفجار بزرگ ارائه شد.در اين الگو فرض مي شود كه ماده ي غالب جهان در لحظات اوليه پس از انفجار ،يك ميدان اسكالر است كه ميدان اينفليتون نام دارد.وجود اين ميدان باعث شده است كه انبساط عالم داراي شتابي مثبت باشد وبدين ترتيب در بازه ي بسيار بسيار كوچكي از زمان،شعاع عالم به مقدار زيادي رشد كرده است. يكي ازمسايل اساسي در كيهان شناسي نوين ،منشآ افت وخيز هاي اوليه ي ميدان تورمي زا در طول اين دوره ،بعنوان هسته ي اوليه ي تشكيل ساختارها مي باشد كه اين الگوي تورمي داراي پيش بيني هايي براي توزيع ناهمسانگردي ها واختلالات مشاهده شده در عالم است. در واقع ساختار هاي بزرگ مقياسي كه در جهان امروز مشاهده مي شوند،از افت وخيزهاي كوانتومي يك ميدان اسكالر در طي دوران تورمي در جهان اغازين ناشي شده اند .اختلال هاي نخستين كه در طي دوره ي تورم ايجاد شده اند، اثرشان روي توزيع ماده وتابش كاملا مشهود است. يكي از مهمترين نتايج مدل هاي تورمي اين است كه وجود طيف هايي براي اختلالات اسكالر واختلالات تانسوري كه به ترتيب عامل ايجاد ناهمگني چگالي ووامواج گرانشي هستند، پيش بيني مي كنند. اختلال هاي نخستين كه در طي تورم ايجاد شده اند ،اثرشان را روي طيف توان CMBنشان مي دهند وقيود قابل مشاهده اي را روي اين طيف ايجاد مي كنند .اثرات اين اختلالات را مي توان با محاسبه ي پارامترهاي اختلالي مدل هاي تورمي روي طيف توان CMB،مشاهده كرد. دراين پايان نامه مطالب، به شرح زير ارائه مي شوند:

   In this work, we investigate optical nonlinear phenomena up to ninth order of hybrid molecule composed of a semiconductor quantum dot near a spherical metallic nanoparticle (SQD-MNP),and a hybrid nanosystem consisting of   two metallic nanoparticles and a semiconductor quantum dot (MNP-SQD-MNP) in the presence of an external field because for some applications higher-order nonlinearities are desired. On the other hand, by using the density matrix approach, the higher order nonlinear susceptibilities such as third, fifth, seventh and ninth order are obtained. We found that the non-linear optical response of these hybrid systems dependent on the interparticle distance, the size of particle, material of the nanoparticle and the dielectric constant of the inviroment. Also, the higher-order nonlinear refractive indices and absorption coefficient related to the nonlinear susceptibilities are derived and numerically discussed.   

  Quantum Radiography or Quantum State Radiography is the process of quantum state reconstruction for the source of quantum systems by measuring on the input systems from the source. In this dissertation we present a demonstration of quantum process radiography for the photon amplifier and dimmer operator.

   The three approach to relativistic generalization of coherent state are discussed in the simplest case of a spinless   article: the standard, canonical, coherent states, the Lorentzian state and the coherent state introduced by Kaiser and independently by Twareque Ali,Antoine and Gazeau. All treatment utilize the Newton-Wigner localization avd dynamics described by saltpeter equation .The behavior of expectation values of relativistic observables in coherent state is analyzed in detail and the Heisenberg uncertainty relation are investigated.

   Geophysical methods are the best techniques to identify and explore groundwater reserves without destructive environmental impacts. Among these methods, electrical resistivity with low cost and acceptable accuracy can play important roles in groundwater exploration. The electrical resistivity method with the Schlumberger arrangement is known as the most common and the most practical geophysical method in groundwater exploration studies. Accordingly, a site investigation was performed in Zangovan plain of Sirvan city located in the Ilam province. The purpose of the geoelectrical study in this plain was to investigate the groundwater status based on the values of apparent electrical resistivity measured using the Schlumberger arrangement, as well as to determine the best location for drilling the wells toward the groundwater exploitations. In this plain, 73 electrical soundings were carried out along ten profiles with Schlumberger arrangement, which were drawn based on the apparent resistivity data obtained from site investigations by GeoSoft software. Besides, the geoelectric sections for each of the profiles were obtained by 1-dimensional and 2-dimensional inversion methods using ZondRes2D software. Finally, the most suitable places for drilling wells were suggested based on the interpretation of the apparent resistivity maps, apparent resistivity sections, geoelectric sections, as well as considering the geological location of the study area.

The cavity which resonates on the continuous and wide of frequency range si- multaneously, without loss of ?nesse and build-up factor known as white light cavity (WLC). Such a cavity operates completely di?erent from the conventional Fabry- Perot cavity. One of the most considerable and interesting applications of white light cavity bandwidth is the production of optical switches with of a wide broad- band and enhancing the sensitivity of gravitational wave detectors which recently has been investigated in various scienti?c researches. In this thesis, the impact of atomic coherence and interference on white light generation by using a negative dispersive medium and tra  arent from Fabry-Perot cavity is investigated. This negative dis- persive medium is studied in di?erent models, such as the ladder-type three-level atomic system and cascade-type four-level atomic system. By driving non-resonant laser ?elds, the Hamiltonian of atomic system in the interaction picture is used to calculate the elements of the density matrix. In the steady state regime, the complex electric susceptibility of the atomic system is calculated up to ?rst order approxi- mation of the perturbation and initial conditions for making white light cavity is achieved. As shown that the white light cavity bandwidth in the three-level atomic system is increased to 40?1 and four-level in single band case to 103? and double band symmetric to 60?. This study can be used for designing and manufacturing of all- optical switches, gravitational wave detectors and sensors in optical communications and quantum information process.

In this study, we investigate the entangled coherent states and their decoherence. We briefly introduce the coherent states which have been identified in physics and then the introduction and creation of   loch coherent states are dealt with.‎‎‎‎ We examine these states from different points of view, namely, group theory, irreducible representations and also from Fock Bargmann's viewpoint. Moreover, we investigate the entangled coherent states which are among the most important states in quantum information processing. ‎‎‎‎‎There are some criteria for the study of these states, including ‎B‎ell inequality, entropy, fidelity and entanglement of formation, which will be explained here in brief. ‎ ‎‎We will examine the qubit of orthogonal coherent states. We present these states on ‎B‎loch sphere.‎ ‎‎‎‎‎In quantum optics, a possible method of producing the entangled states of two mode of light field, is transmission of single mode state and its interference with another state (vacuum state) on a beam splitter. ‎‎‎We will calculate the amount of entanglement in these states which can be produced in beam splitter. The entangled states which are produced by using this method, are the entangled coherent states.‎ ‎‎‎‎‎‎We will describe the decoherence of ‎these‎ coherent state ‎qubits‎‎ and finally, using the adaptive Bloch sphere, we will provide an interpretation of these states.‎‎‎‎‎

  This thesis, is a resarch about the optical absorption and thermal properties of a bilayer-graphene’s lattice. to obtain the desired parameters, we first need to calculate the Hamiltonian of tight binding model, that once in the base state and again with the consideration of the factors of the disorder. So , we consider as a disturbance factor, an in-site difference between the two atoms in a unit cell as a gap parameter, and a difference in energy between the atoms of a sheet with another sheet as a bias voltage. Using Hamiltonian’s the tight binding model and the Green's function, we can calculate jumping to neighbors to describe the dynamics of the orbital electrons of Pz and the density of state’s electron of bilayer-Graphene’s lattice in both simple and bernal stucking. Then, with the help of the linear response theory, we can calculate the electrical conductivity of the system in terms of the frequency of the electromagnetic wave spectrum. With the electrical conduction’s equation , we can study the frequency behavior of the optical absorption spectrum of the system by applying variations in the gap parameters, bias voltage and temperature, according to the stucking of the atoms.

    In this thesis, using the Green’s functions approach and Harrison’s tight-binding Hamiltonian model, we want to study the electronic identity and electronic heat capacity of the black and blue phosphorenes being compared with graphene. The results show that both kinds of phosphorenes are semiconductor. Observed in both is the Schottky anomaly at thermal provocations near the energy gap. Furthermore, employing the Harrison’s model for blue phosphorene provides more details for analisis of partial contribution of the various atomic orbitals.

  According to quantum theory the energy can exchange between physical system is quantized. Naturally, the study of the physical behavior of light can also follow this law. To consider the signature of the quantum nature of light from the theoretical perspective is required to quantize the electromagnetic field. The important field’s states are number states, coherent states and squeezed states. During the second half of twentieth century, field quantisation and field’s states were successfully detected and produced.  Keywords: Field Quantisation – Coherent States – Squeezed States

A diffraction grating is a key element in optical spectroscopy and laser beam splitting. Production of such elements is a technologically complicated and expensive procedure. But the collection of ridges on the individual scales on the wings of a butterfly act as transmission diffraction gratings. Compound microscopes show such a micrometer periodical structure, but are not sufficient precise instrument to determine grating constant of butterfly in the range of 10-7 or 10-8 m. To determine grating constant one could use such instruments as SEM and TEM, but these are expensive.In this thesis, we first apply three methods to define grating constant of CENCO transmission gratings: 1) Diffraction grating spectroscopy, 2) Compound microscopy and 3) Diffraction of a He-Ne laser. Then we apply compound microscopy and laser diffraction methods to determine grating constant of butterfly. The results show that by laser diffraction one could precisely determine the grating constant of butterfly.This research was done using optical elements and instruments of Laboratory of Optics (2217) and research Laboratory of Laser (2218).Keywords: Diffraction, He-Ne laser, wings of butterfly, compound microscope, diffraction grating.

  حالت هاي همدوس عموما يك ارتباط تنگاتنگ بين روابط كلاسيك و كوانتومي يك سيستم داده شده را فراهم مي آورد. اين حالت ها در حقيقت ويژه بردارهايي خاص در فضاي هيلبرت مي باشند كه حداقل داراي سه ويژگي مهم پيوستگي، نرماليزه پذيري و رابطه هماني را دارا مي باشند. كوانتش يك نگاشت انتگرالي مي باشد كه ما را از فضاي كلاسيك به فضاي كوانتومي مي برد. در اين پايان نامه حالتي را در نظر مي گيريم كه در مكانيك كوانتومي استاندارد وجود ندارد و مكانيك كوانتوم استاندارد قادر به توجيه آن نيست، براي حل اين مشكل از حالت هاي همدوس كمك مي گيريم. با استفاده از كوانتش انتگرالي برزين، مقدار كلاسيكي تابع( مشاهده پذير ) را در نگاشت انتگرالي قرار داده و معادل كوانتومي آن ( عملگر ) را بدست خواهيم آورد. فضاهاي ناجابجايي دو بعدي مي توانند سطح تخت ناجابه جايي و يا سطح كره ناجابجايي و يا هر سطح خميده ديگر باشند. در اينجا حالت هاي همدوس را در سطح تخت ناجابجايي (صفحه ناجابجا) بررسي مي كنيم. منظور از ناجابجايي مختصات، ناجابجايي مكاني است و ناجابه جايي را بين مختصه هاي زماني در نظر نمي گيريم زيرا از لحاظ مفاهيم يكتايي و عليت دچار مشكل مي شويم. همچنين سه شرط پيوستگي، نرماليزه پذيري و رابطه هماني را برا ي حالت هاي همدوس در فضاي ناجابجا بررسي مي كنيم

Channeling motion of charged particles in crstalline materials was considered first by Lindhard in 1965. In subsequent years, Kumakhov investigated in a simple form the channeling motion and radiation of relativistic light charged particles, such as electron and positrons, in crystalline materials. In this thesis, we consider from the classical and quantum points of view the dynamic of channeling motion of charged particles in crystals and resulting channeling radiation will be considered.

  Black holes are objects in the cosmos have amazing compact and heavy objects that even light does not pass through the discovery of quasars, black holes were discovered fact. Super red shift quasars Vtabshy a thousand light years are less than the diameter of a typical galaxy

  In recent decades, study on soliton systems was very controversial and has attracted attention of many researchers, including Iranian researchers. The study in this field in order to study their behavior plays a significant role. Therefore deal knowing or combine or create them have most important. This thesis, first with a brief overview on soliton concepts and importance of their study started and then types studies and computational and numerical methods examined for it. Studies on considered samples were very long, and beyond the scope of this thesis, therefore, only be satisfied on a brief review. According to the conducted surveys, several systems already have been examined. Therefore, based on our knowledge of those studies should in provide a new method and of course reliable proceeded.

In recent years, much attentions have been paid to the metal-semiconductor nanostructures due to their potential applications in science and technology, and also in enhancing the nanoscale sensors and optical devices. In addition, the exciton-plasmon interactions makes them a hot topic in the field of nanoscience and plasmonics. Interaction ‎between ‎noble ‎metal ‎plasmons ‎and ‎semiconductor ‎exciton‎s could lead to interesting nonlinear optical effects such as electromagnetically induced tra  arency (EIT) and slow light. Moreover, this phenomena would open a new route for designing new optical sensors and devices based on plasmon-exciton interaction. In this study, the electrodynamic of concentric cylindrical nanoshells in the framework of the Mie formalism has been investigated theoretically . By introducing the TE and TM modes in cylindrical geometry, the scattering coefficients for core-shell and multishell nanoparticles has been calculated. By considering an effective dielectric function for the system and using the Clausius-Mossoti relation, the group velocity in the medium has been formulated. Furthermore, the induced electromagnetic tra  arency in a system consisting of a dielectric slab doped with cylindrical nanoparticles sandwiched between two metallic parallel plates has been investigated.The influence of some key parameters such as the thickness of layers, the size and composition of nanoparticles and slabs on EIT has been shown and analyzed.