The statistical error in any estimation can be reduced by repeating the measurement and averaging the results. The central limit theorem implies that the reduction is proportional to the square root of the number of r...
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The statistical error in any estimation can be reduced by repeating the measurement and averaging the results. The central limit theorem implies that the reduction is proportional to the square root of the number of repetitions. Quantum metrology is the use of quantum techniques such as entanglement to yield higher statistical precision than purely classical approaches. In this Review, we analyse some of the most promising recent developments of this research field and point out some of the new experiments. We then look at one of the major new trends of the field: analyses of the effects of noise and experimental imperfections.
Pulse-shaping techniques, in which user-specified, ultrashort-pulse fields are synthesized by means of parallel manipulation of optical Fourier components, have now been widely adopted(1-6). Mode-locked lasers produci...
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Pulse-shaping techniques, in which user-specified, ultrashort-pulse fields are synthesized by means of parallel manipulation of optical Fourier components, have now been widely adopted(1-6). Mode-locked lasers producing combs of frequency-stabilized spectral lines have resulted in revolutionary advances in frequency metrology(7-11). However, until recently, pulse shapers addressed spectral lines in groups, at low spectral resolution. Line-by-line pulse shaping(12), in which spectral lines are resolved and manipulated individually, leads to a fundamentally new regime for optical arbitrary waveform generation(13), in which the advantages of pulse shaping and of frequency combs are exploited simultaneously. Here we demonstrate programmable line-by-line shaping of more than 100 spectral lines, which constitutes a significant step in scaling towards high waveform complexity. optical arbitrary waveform generation promises to have an impact both in optical science ( allowing, for example, coherent control generalizations of comb-based time - frequency spectroscopies(10)) and in technology (enabling new truly coherent multiwavelength processing concepts for spread-spectrum lightwave communications and light detection and ranging, lidar).
Charge-Coupled Device (CCD) area image detectors of the interline-transfer type include a design feature which enables analog image data to be electrically inserted into the vertical registers via a horizontal input r...
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Volume holographic memories (VHMs) are a candidate technology for next-generation high-density and high data-rate digital storage. Capacities greater than 1 Terabit are promised, available at read-out rates exceeding ...
Volume holographic memories (VHMs) are a candidate technology for next-generation high-density and high data-rate digital storage. Capacities greater than 1 Terabit are promised, available at read-out rates exceeding 1 Gigabit per second. The capacity target will be achieved through two mechanisms. First, retrieval in a VHM reconstructs a holographic page (a two-dimensional image) captured on a CCD (charge-coupled device) camera. Each page represents on the order of one million bits of data, by encoding the data as bright and dark pixels in the 1024 x 1024 stored/retrieved image. Second, due to the thickness of the recording medium, a large number of such pages can be recorded in the same volume of material. In this dissertation we address some of the difficult technical issues that either currently limit the VHM system design, or are expected to become a limiting factor in the future. The first such concern involves how to process the simultaneous optical arrival of one million pixels. In high-density storage, there will be significant cross-talk between pixels which limits the storage capacity. We develop a novel highly-parallel focal-plane processor, which can significantly improve the system capacity by performing reliable detection in the presence of optical blur and alignment errors introduced by the imaging system. A fabricated proof-of-concept VLSI design is described. Another fundamental noise source is caused by the cross-talk between holographic pages. Reconstruction of the desired data page reconstructs every page in the memory, albeit at a very low relative diffraction efficiency. As the number of multiplexed pages increases, the cross-talk from the other pages can constitute a significant optical field noise source. Apodization seeks to either suppress this noise source or control it such that system tolerances can be relaxed. Bright data pixels are stored by altering the material properties of the crystal. However, dark pixels require no adjustment to
The state of the art of silicon optoelectronic integrated circuits (OEICs) is described. It is verified that silicon OEICs achieve both high sensitivities and high bandwidths up to the GHz range. Silicon OEICs, theref...
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ISBN:
(纸本)0819443395
The state of the art of silicon optoelectronic integrated circuits (OEICs) is described. It is verified that silicon OEICs achieve both high sensitivities and high bandwidths up to the GHz range. Silicon OEICs, therefore, compete successfully with III/V OEICs for low-cost high-volume applications. Results of advanced monolithically integrated photodiodes available in CMOS and BiCMOS technologies are presented. The technological aspects for the monolithic integration of photodiodes are addressed and tile properties of the so-called double photodiode and of the pin photodiode are described. Tile innovative integrated double photodiode allowing data rates of 622 Mb/s is available in standard silicon technologies without any process modification, For the integration of tile pin photodiode allowing data rates of higher than I Gb/s usually at least one additional mask is required. It will be shown that the pin photodiode also can be implemented without an additional mask. The second main part of this article covers circuits of optical fiber and interconnect receivers with data rates of up to 1 Gb/s as well as advanced DVD pick-up OEICs with bandwidths of up to 150 MHz. Tile fiber receivers achieve an effective transimpedance of 45.9 kOmega and the sensitivity of this OEIC in a 1.0 pm CMOS technology with a data rate of 1 Gb/s is improved by 9 dB compared to that of a published OEIC in a 0.35 pm CMOS technolgy.
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.
The advent of second-generation opticalstoragetechnology and user experience with PACS dictate a new look at PACS long-term database organization and optical archive strategy. optical disk drives are growing faster ...
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Based on the actual engineering perspective, this paper presents the site of pumped storage power plants, which is determined by collecting and processing elevation data, river system data, road data, meteorological d...
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