opticaldatastorageadvances and compact disc market acceptance have led to the development of a new mass storage medium, CD-ROM (Compact Disc-Read Only Memory). This article provides a brief overview of the technolo...
The diffractive optical element (DOE) has the transformation function of wavefront, and its applications are forming or homogenization of beam, and aberration correction, and so on. In this study, we evaluate possibil...
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ISBN:
(纸本)9780819496058
The diffractive optical element (DOE) has the transformation function of wavefront, and its applications are forming or homogenization of beam, and aberration correction, and so on. In this study, we evaluate possibility as storage application of the DOE. The opticaldatastorage using the DOE is thought of as a kind of holographic datastorage (HDS). In the HDS, digital data is recorded and read out as modulated 2-dimensional page data, instead of bit-by-bit recording in conventional opticalstorages. Therefore, HDS actualize high data transfer rate. We design and optimize phase distribution of the DOE using the iterative method with regularization. In the optimization process, we use iterative Fourier transform algorithm (IFTA) that is known as Gerchberg-Saxton (GS) algorithm. At this time, the regularization method is adopted to suppress minute oscillation of the diffraction pattern. Designed and optimized DOE is fabricated by ultraviolet (UV) nanoimprinting technology. High productivity can be expected by adopting nanoimprinting technology. DOEs are duplicated on the silicon (Si) substrate as reflection-type elements. Fabricated DOE is evaluated in the experiment. We verify that DOE for opticaldatastorage can be actualized through our approach.
optical character recognition is a method of the renovation of pictures of printed text, handwritten documents andtypewritten documents into a document recognized by the machine. This can be used for editing, reductio...
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ISBN:
(纸本)9781538609262
optical character recognition is a method of the renovation of pictures of printed text, handwritten documents andtypewritten documents into a document recognized by the machine. This can be used for editing, reduction in storage space etc. So, basically, it relates to posses of teaching and recognition of data. Hence, here a hand written document which is in a form of some local language characters except than English. In this paper, we are using the Gujarati Characters for the recognition into the machine editable format. Deep learning is the method used for identity recognition which will depend on the man-made neural network. Deep learning involves a proper focus on right features of the image to recognize themselves with a negligible assistance from the program. Neural network evolved considering the concept of biological neurons. Accuracy and efficiency are improved by use of deep learning for character recognition.
A new optical card without pre-formatted pattern and tracking servo is proposed. An optical read/write system has been constructed and its stable operation verified. It is expected that this system will be further ref...
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ISBN:
(纸本)0819403717
A new optical card without pre-formatted pattern and tracking servo is proposed. An optical read/write system has been constructed and its stable operation verified. It is expected that this system will be further refined as micro-optics technologyadvances.
A diffractive superresolution element placed at the exit pupil can effectively increase the resolving power of an optical system for opticaldatastorage. The theory of linear programming is suggested in this paper to...
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ISBN:
(纸本)0819447196
A diffractive superresolution element placed at the exit pupil can effectively increase the resolving power of an optical system for opticaldatastorage. The theory of linear programming is suggested in this paper to design the diffractive superresolution elements, which can get globally optimal solutions. Examples of design and some limits of optical superresolution are presented, and a comparison between the results for a uniform incident field and those for a Gaussian incident field is performed.
This article investigates the dependency between advances in chip technology, architectures, and security. Two major properties of secure systems are analyzed in this context: data separation of different applications...
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ISBN:
(纸本)9781538654040
This article investigates the dependency between advances in chip technology, architectures, and security. Two major properties of secure systems are analyzed in this context: data separation of different applications and secure storage of cryptographic keys. We discuss first examples for compromising data separation, e.g. the Rowhammer attack on modern DRAMs, enabled by the sensitivity of shrinked DRAM cells for crosstalk effects, or Meltdown and Spectre attacks using cache side channels. These attacks show the dependency between data separation and advances in technology and architecture. Even more powerful attacks exploiting bus and network-on-chip traffic are possible. Another area where technology meets security is the storage of cryptographic keys. New technologies offer new ways to realize non-volatile memory (NVM) for secret datastorage and to implement physical unclonable functions (PUFs), which generate the key during system start and do not store it permanently in NVM. To enable good PUFs, technology and security people should work together as early as possible in the development phase, since PUFs must be characterized carefully. Ideally a PUF module is provided as a characterized and reliable security primitive in the design library. If we manage to take security already into account in early technology development phases and during architecture definition, we will get more secure systems-on-chip in the future.
Recent advances in opticalstoragetechnology, both two-dimensional and three-dimensional, suggest that optical memories can be used for applications requiring massive archiving volumes. In order to use optical memori...
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ISBN:
(纸本)078033650X
Recent advances in opticalstoragetechnology, both two-dimensional and three-dimensional, suggest that optical memories can be used for applications requiring massive archiving volumes. In order to use optical memories in such applications we need to interface them with electronic computers. Our paper discusses the aspects of this interface design.
The first-generation digital video disc - random access storage (DVD-RAM), has a storage capacity of 2.6 Gbytes per side by adopting phase change media, Land&Groove recording, and the mark-length recording method....
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ISBN:
(纸本)0780338855
The first-generation digital video disc - random access storage (DVD-RAM), has a storage capacity of 2.6 Gbytes per side by adopting phase change media, Land&Groove recording, and the mark-length recording method. In DVD-RAM technology, the write strategy is a key technology for ensuring drive reliability and interchangeability of DVD-RAM discs from many manufacturers. A storage capacity of 4.7 Gbytes per side is required for the next generation DVD-RAM. Furthermore, in the future DVD-RAM, much larger storage capacities can be achieved using a bluish-purple laser diode. A DVD-RAM drive with a phase-change disk can easily achieve backward compatibility across generations.
Inter Satellite Links (ISL) are essential to connect Satellites operating in a constellation. If these ISLs could manage high data rates in Gigabit per seconds the network becomes a broadband connectivity services. Ne...
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ISBN:
(纸本)9781538694480
Inter Satellite Links (ISL) are essential to connect Satellites operating in a constellation. If these ISLs could manage high data rates in Gigabit per seconds the network becomes a broadband connectivity services. New possibilities for data exchange and independencies from ground networks are offered. LEO satellite constellations with low latency of data streaming, are very attractive as a backhaul infrastructure to connect people worldwide like a Space based Internet or to address Internet of Things (IoT) applications on a global scheme. optical Inter-Satellite Links (OISL) combine very high data rates with resilient performance. Due to its narrow beam and a coherent detection technology without beacons, these OISLs a very robust. As the optical beams are much narrower than RF beams, no interference with other potential optical communication systems will occur and thus offer high operational security and immunity to interference sources, jamming and eavesdropping. An obvious advantage of the optical ISL is the fact that the frequency usage is not regulated by ITU, which makes the planning and operation of a navigation constellation much easier. OISLs are realized by Laser Communication Terminals (LCT) on each end of the link. The technology readiness of Laser Communication Terminals is TRL9. This paper gives an overview on the current status and on the future developments of Laser communication terminals in the various applications.
Results of implementation of technical solution for long term datastoragetechnology on the basis of single crystal sapphire are presented. The effect of birefringence on the distribution of the focused laser beam th...
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ISBN:
(纸本)9781628412284
Results of implementation of technical solution for long term datastoragetechnology on the basis of single crystal sapphire are presented. The effect of birefringence on the distribution of the focused laser beam through a uniaxial birefringent medium having a vertical orientation of the optical axis is analyzed. An expression for the calculation of the geometric aberrations of the focused laser beam in single-crystal substrate of the optical disc has been presented. It is shown that the problem of data reading through a substrate of negative single crystal sapphire can be solved by using for reading a special optical system with a plate of positive single crystal materials. The experimental results confirm the efficiency of the proposed technical solution.
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