Four novel photochromic dithienylethenes compounds, 1,2-bis[2-methyl-5(p-fluorophenyl)-3-thienyl]perfluorocyclo-pentene (1a), 1, 2-bis[2-methyl-5(p-ethox yphenyl)-3-thienyl]perfluorocyclopentene (2a), 1,2-bis[2-methyl-5(p-N,N-dimethylaminophenyl)- 3 -thienyl]perfluorocyclopentene (3a) and 1,2-bis(2-methyl-5-naphthalene-3-thienyl)perfluorocyclopentene (4a) were synthesized. Their optoelectronic properties, such as photochromism in solution as well as in PMMA amorphous, fluorescence and electrochemistry properties were systematically investigated. These dithienylethenes have shown good photochromic behavior both in solution and in PMMA amorphous film. All of them exhibited relatively strong fluorescence. With the increase of their concentration in a THF solution, their fluorescence spectra showed a bathochromic shift. The irreversible anodic oxidation of la, 3a and 4a occurred when performing cyclic voltammetry tests. Moreover, dithienylethene la showed remarkable multi-color electrochromic properties during the anodic polarization. In addition, photo-mode multi-step opticalstorage using 2a and 3a as recording medium was performed successfully.
Photopolymer is an optimum material for practical holographic storage because of low cost and good characteristics. A new epoxy resin-photopolymer is reported. Polymeric binder is epoxy resin whose refractive index is...
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ISBN:
(纸本)0819455989
Photopolymer is an optimum material for practical holographic storage because of low cost and good characteristics. A new epoxy resin-photopolymer is reported. Polymeric binder is epoxy resin whose refractive index is high, but the monomer's refractive index is relatively low. The design can make monomer transfer freely in rigid frame, so we can realize no-shrinking recording and stabilize the recorded hologram. Simple grating is recorded in films, then we obtained the relationship curve between the exposure energy and diffraction efficiency by sending a single beam into the photopolymer film. According to the exposure curve, there is a recording delay, so the pre-exposure is needed to sensitize the material. In order to avoid cross-talk between contiguous holograms, angle selectivity of the material is measured. Then we investigate how diffraction efficiency is distributed in all multiplexed holograms with equal-time exposure. One method of calculating exposure schedule for multiplexing holograms in photopolymer with equal efficiency is presented. By using such exposure schedule, holograms are recorded at a single location by angle multiplexing, and the uniformity of their diffraction efficiency is remarkably improved. After iterating the procedure, it is possible to achieve much more uniform diffraction efficiency.
The following is a historical perspective of the significant technological demonstrations that shaped the history of high power semiconductor lasers, This article is not meant to be a re view article, as there are muc...
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The following is a historical perspective of the significant technological demonstrations that shaped the history of high power semiconductor lasers, This article is not meant to be a re view article, as there are much better review articles and reviewers available, nor would the article try to cover all of the contributions to such a rich technology. Nonetheless, this article will, anecdotally, present a perspective on the technological advances that resulted in the enabling technology of high power semiconductor lasers for applications such as fiber optic communications, datastorage, and material processing.
This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. data is stored in a loop. The amount of data stored is the data rate times the storage time. Lyteloop use...
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ISBN:
(数字)9781510629448
ISBN:
(纸本)9781510629448
This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. data is stored in a loop. The amount of data stored is the data rate times the storage time. Lyteloop uses: (i) highly multiplexed optical communications to maximize data rate, and (ii) a long light path, to maximize length of time it takes light to traverse the full storage loop. Lyteloop is developing datastorage in motion in 4 domains : fiber, space, and two forms of near vacuum chambers. Multiplexing is done across very wide wavelength ranges, and many spatial modes. OEM modes will be used in free space at the shorter wavelengths, and other spatial mode structures will be used in fibers. Multiple cores will be used in fibers. A 1.5 Gigabyte demonstation datastorage unit has been built in fiber, and is described, along with its performance. We are starting a free space prototype. Lyteloop builds on, and advances, both free space, and fiber, high data rate communications technology as a method of storing data in motion. We also have patent pending approaches to increase the length of the data stroage loop. Less complex, and lower power, signal regeneration will be required to achive Lytelops's goals.
In this paper, a finite-element model of a slim optical disk drive is developed to investigate the transient response of the sled base and disk. The model is simplified by using beam, shell and lumped parameter elemen...
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In this paper, a finite-element model of a slim optical disk drive is developed to investigate the transient response of the sled base and disk. The model is simplified by using beam, shell and lumped parameter elements, in order to decrease the computational time. After the dynamic characteristics of the finite-element model have been verified by modal test, the shock response is obtained and compared with the results of a drop test. Finally, dynamic characteristics are modified to improve the shock performance.
Rotational speed of optical drives and servo speed of optical pick-up actuators should be higher to meet high performance for optical drives. One of the methods to achieve such a high performance product is to increas...
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ISBN:
(纸本)0819455989
Rotational speed of optical drives and servo speed of optical pick-up actuators should be higher to meet high performance for optical drives. One of the methods to achieve such a high performance product is to increase an input power for the coil, but a heat problem generated by the coil will become serious. Two kinds of new ferrofluids have been designed to transfer a heat from the coil of optical pick-up actuator. Their physical properties have been properly designed to be functioned at a wide operating temp. and various aspects of their reliability including resistance for deterioration to high temp. and humidity, etc., have been evaluated. Also, they have been applied to optical pick-up actuators and the properties of ferrofluids such as heat transfer and shock resistance have been examined. The life tests showed that the new ferrofluids had at least two times longer life and a smaller viscosity change than CF-3A, which has been used in commercially available optical pick-up actuators. The new ferrofluids could tolerate the shock of 500 G without a ferrofluid splash, the coil temp. with the ferrofluid was about 10 degrees C or more lower than the one without it at the same input power.
optical Disk Drives (ODD) uses chipsets to implement the various functions required in its operation. The chipsets always have fixed algorithm that make it impossible for the researches to carry out any experiments on...
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ISBN:
(纸本)0819455989
optical Disk Drives (ODD) uses chipsets to implement the various functions required in its operation. The chipsets always have fixed algorithm that make it impossible for the researches to carry out any experiments on newly developed algorithms. To overcome this difficulty, this study has constructed a test platform for the ODD experiments. This platform solution allows for software implementation of all the necessary functions in the CD/DVD system. The researchers can easily alter the software to change the existing functions of to implement new functions for different applications. The hardware of this development system is mainly composed of MSC-51, FPGA, DSK, AD/DA module, and an analog mother board. The MSC-51 is responsible for applying commands and setting functions, and it plays a role of master in the system. The TI DSK 6711, served as a slave, is responsible for implementing new algorithms and focus is mostly focused on servo control. The FPGA is responsible for handshaking among the DSK, the MSC-51, and the AD/DA module board;it also provides the register banks for the MSC-51 and the DSK. The purpose of the AD/DA module board is to establish communication link to the physical world. There are two A/D chips of eight channels and four D/A chips of four channels on the AD/DA module board. There are also a pre-amp chip and a driver on the analog mother board to amplify the signal on the ODD and to drive a DC motor. Users only have to change the pre-amp and ODD for different type of ODD.
In the past few years microfilm has gained new research interest as a medium for long-term storage of digital data. This became particularly possible by recent advances in laser film recording technology. In contrast ...
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ISBN:
(纸本)9781424456383
In the past few years microfilm has gained new research interest as a medium for long-term storage of digital data. This became particularly possible by recent advances in laser film recording technology. In contrast to other optical or magnetic storage media, the microfilm digital channel (MDC) still has been subject to characterization in only a few publications. In this paper we investigate iterative channel codes for the MDC, in particular low-density parity-check and turbo convolutional codes. Simulation results show that practically error-free storage can be achieved with code rates even above 0.85 on a monochrome MDC with binary amplitude-shift keying modulation.
Transferring data packets over a network is more efficient when lossless data compression is applied before transmitting. Storing that same data requires less space if compression is applied prior to writing the data ...
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ISBN:
(纸本)9781934272527
Transferring data packets over a network is more efficient when lossless data compression is applied before transmitting. Storing that same data requires less space if compression is applied prior to writing the data to the storage media. Higher data rates and rapidly expanding storage requirements drive the need for better compression solutions. Power conservation strategies also play an important role today in developing data management systems. technologyadvances are enabling products to meet these developing and growing needs.
We present the experimental realization of a compact and fully automized volume holographic memory based on phase-coded multiplexing that is capable of both, high-resolution analog image and digital datastorage, havi...
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