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NRC Research Groups |
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Research Groups Optoelectronics | The main research activity of this laboratory is based on the industrial and semi-industrial projects in the field of optoelectronic and semiconductor devices. These projects are done by the PhD and MSc students. Some of these works are the design and simulation of photonic crystal devices, photonic crystal fibers, semiconductor lasers, photo detectors, solar cells and so on. At present, the most researches in this laboratory are on the solar cells. One of the projects is being done in order to fabricate the laboratory sample of solar cells based on GaAs. Firstly, the design and simulation of the proper solar cell structures such as GaAs and AlGaAs/GaAs has been done. Then, the fabrication of the primitive sample is being done with choosing the best structure and finally the final sample will be fabricated after the test and optimization of samples. Also, one of the main issues for improving the solar cell characteristics is utilizing the suitable antireflection coating and presenting the novel structures for it. In order to achieve these purposes, we are working on the antireflection coatings used in new generation solar cells such as thin film and quantum dot solar cells and cells based on the concentrators. For more information please click here | Quantronics | Quantronics is composed of two words: Quantum and Electronics. Thus contains two scientific fields. The main research activity of this laboratory is quantum communication and optical quantum computation. Quantum entanglement lays at the heart of quantum information processing (QIP), which over the past twenty years has become an emerging field of modern physics. QIP can mainly be divided into the two areas of quantum communication and quantum computation. Quantum communication describes the transfer of quantum states over large distances, which can lead to drastic improvements in security – quantum cryptography – and channel capacity – quantum dense coding. It further covers the distribution of bi- or multi-partite entanglement between different parties, separated by large distances. Quantum computation is dedicated to the implementation of algorithms that exploit the superposition character of quantum entanglement to dramatically speed up computational tasks such as a reduction of time needed to search an unsorted database of N elements. Any classical algorithm necessitates N operations to accomplish this task, whereas a quantum algorithm only needs N1/2 operations. Probably the most famous quantum algorithm is Shor’s algorithm to factorize large numbers. Its introduction in 1994 has jump started and fueled tremendous effort in the new field of QIP, both on the theoretical and experimental side. For more information please click here | Nanoelectronics | One of the most important aspects of nanotechnology is its multi-disciplinary aspect. The current structure of training program in most of the universities has some shortcomings for nanotechnology experts. Therefore training programs need to be optimized. The factors by which the way toward long-term goals of nanotechnology is being provided in time period less than 20 years are as follows: establishing research centers and applied laboratories of nanotechnology and multi-disciplinary research programs and groups in universities. Hundreds of billions of dollars investments in the field of nanotechnology by developed countries like Japan and American indicates the nanotechnology’s universal importance. In Iran there is a great deal of scientific potential in order to conduct nanoelectronic researches. As a matter of fact, published articles in authoritative international journals and successful research projects represent that there is little distance between Iran and developed countries in this field; therefore, the competition is possible. Research contexts in this laboratory include the factors like quantum transmission, single-electron devices, applying nanoparticles to fabrication of photodetectors with ZnO and molecular nanoelectronic. It has been predicted that by means of equipping the laboratory in future, it is possible to conduct practical activities like using electronic microscopes in order to measure atomic dimensions and molecular ordering, identifying three-dimensional features and nanoelectronic device surface, controlling molecular ordering and fabrication of photodetectors and so on. For more information please click here | Systems | A reliable attitude determination system is essential for a space mission to be successful. An attitude determination system tells to the spacecraft or satellite how much it must turns until its reciever and sender place toward the earth and also its solar arrays place toward sun. There are several meaturment instrument such as gyroscope, sun sensor, star tracker that can provide attitude information. Amoung them, star tracker is the most accurate one. A star tracker allows attitude estimation without any previous knowlage of spacecraft attitude. Also they can provide 3D information. Besides, they do not need any extra instrument to provide attitude information. A typical star tracker functions as below: - Camera of star tracker take an image from stars in the sky.
- An algorithm that calls centroid algorithm, extract stars from image.
- A star identification algorithm extract some features from these stars.
- There is an on-board data base which is generated from all sky stars that have a certain magnittude. This catalogue contains the same feature as star identification algorithm extract in previous step. The data base is constructed from existent star catalogue such as hyparcos and bright star catalogue.
- The features which extract from the image of stars, compare with the features in the catalogue. Wherever they match together, the attitude of spacecraft can be estimated.
A star tracker operates in two different mode: initial attitude acquisition mode and tracking mode. In initial attitude acquisition the previous attitude information is not available so the data base must search completely until a match is found. When attitude of spacecraft was found, star tracker enters tracking mode. This mode is the normal operating mode of star tracker. In tracking mode, there is no need to search whole data base and just part of data base which is near the previous atittude is searched. In this paper our focus is on the initial attitude acquisition mode. A lot of algorithm for initial attitude acquisition is introduced. These algorithms can be place in two different classes. In the first class, stars consider as vetices of a graph. Different features can be extracted such as: distance between two stars, angulares or area which three stars create together. Polygon algorithms such as planar triangles , spherical triangles , oriented triangles and pyramid algorithm categotises as this class. The algorithms which places in the second class, assotiate each star with a well define pattern that can be determined by the surrounding star field. Grid algorithm, neural network and genetic algorithm place in this class. We are working on a prototype of star tracker that have this ability to become commercial star tracker. For more information please click here | Microelectronics | Nanoptronics research center is to advance microelectronics science, technology, and education, by providing facilities which encourage interdisciplinary research and educational activities. The microelectronics laboratory is positioned to provide critical resources and infrastructure to support the education of quality students and renowned research faculty. Theoretical and practical aspects of techniques utilized in the fabrication of semiconductor devices. In this center techniques of chemical vapour deposition and diffusion; advanced concepts of contamination control; defect-free processing; complete characterization including junction penetration, resistivity, and oxide thickness, Switching speed, junction characteristics, leakage and gain, ion implantation, and method of fabrication are studied. For more information please click here |
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