The novel optical coding scheme for all-optical analog-to-digital conversion has been proposed, in which asymmetrical Y-branch waveguide structures have been introduced to achieve the desired optical power splitting. ...
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The novel optical coding scheme for all-optical analog-to-digital conversion has been proposed, in which asymmetrical Y-branch waveguide structures have been introduced to achieve the desired optical power splitting. The optical performance has been simulated by using finite-difference beam propagation method (FD-BPM), which shows that the designed component exhibits good coding performance. Experimentally, the optical coding component has been fabricated and measured. The optical power contrast between bit code 1 and Oat output port is more than 37 dB, and measured imbalance of output power is less than 1.5 dB for bit code 1. (C) 2011 Elsevier B.V. All rights reserved.
We present a technique for remote monitoring of time-division multiplexed passive optical networks (TDM-PONs) based on fiber Bragg grating (FBG) encoders interrogated by a broadband incoherent optical frequency-domain...
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We present a technique for remote monitoring of time-division multiplexed passive optical networks (TDM-PONs) based on fiber Bragg grating (FBG) encoders interrogated by a broadband incoherent optical frequency-domain reflectometer (I-OFDR). Compared with previous approaches, the proposed system features inherent high robustness against temperature-induced wavelength shifts in the FBG-encoders. The I-OFDR-based monitoring unit enables measurements with high resolutions and sensitivities without the need for high peak-power monitoring signals, which minimizes its footprint on the data links. We carry out a comprehensive description of the system and we evaluate its capacity in terms of signal-to-interference ratio (SIR). We show that, through suitable windowing, a SIR >= 20 dB can be achieved in highly-dense TDM-PONs having more than 128 customers through the use of moderate measurement bandwidths of 300 MHz. We experimentally demonstrate the proposal in a TDM-PON carrying a 10 Gbps downstream data signals, obtaining a negligible impact in the downlink performance, such as the bit error rate remains below 10(-6).
Fluorescent magnetic microbeads can be potentially used in optical coding of biomolecules. The currently commercially available microbeads so far suffer polydispersity in both size and fluorescence intensity. Large st...
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Fluorescent magnetic microbeads can be potentially used in optical coding of biomolecules. The currently commercially available microbeads so far suffer polydispersity in both size and fluorescence intensity. Large statistical fluctuations in intensity level are quite detrimental for their use in optical coding applications. To optimize them for multiplexed optical coding of biological molecules, besides monodispersity, statistical fluctuations in intensity of beads need to be maintained as low as possible (< 1 % and less) in order to obtain a large number of codes. Here, we show that fluorescent and magnetic droplets synthesized through a simple and elegant oil-in-water microemulsion technique can have statistical fluctuations as low as < 1 % with a number of fluorescent labels. (C) 2006 Elsevier B.V. All rights reserved.
optical coding has numerous properties that make its application to remote monitoring and failure detection in passive optical networks very attractive. Several approaches for encoder implementation have been proposed...
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ISBN:
(纸本)9781467384667
optical coding has numerous properties that make its application to remote monitoring and failure detection in passive optical networks very attractive. Several approaches for encoder implementation have been proposed. One of them consist of a couple of fiber Bragg gratings forming a cavity producing multi-level periodic codes. In this work we propose and evaluate the performance of two new encoder schemes based on this premise. These new encoders generate codes with Hamming weight 2 and 3 in order to improve the performance of multi-level periodic codes. We observe that the proposed coding schemes show a better performance under certain scenarios.
The methods of increase the protective properties of holographic elements by using hidden image are discussed. The extension of the new method of wave equation solution is useful for providing analytical studying and ...
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ISBN:
(纸本)0819464260
The methods of increase the protective properties of holographic elements by using hidden image are discussed. The extension of the new method of wave equation solution is useful for providing analytical studying and numerical modeling of diffraction on amplitude-phase discrete mask. Possibilities of its practical application for structured light beam generation and wavefront reconstruction is considered. Conclusions regarding the possibilities of the representation of the arbitrary fields by using the discrete matrix of elementary diffractive aperture cells for an enhancement of the iteration algorithm of hologram synthesis are obtained. The method proposed of computer-generated holograms (CGH) synthesis enables one to synthesize CGH's and to simulate the digital image processing techniques for hidden image coding. The further improvement of this approach of coding amplitude-phase masks for both recording and reading of hidden image by holographic security devices is proposed. By using coding phase mask with quasi-stochastic distribution for diffraction pattern writing as additional structure on the protective hologram are explained. It is shown that computer generated hologram (CGH) can restore spatial structure represented by optical singularities. The conditions of reconstruction of the hidden image are discussed in case of encoding and decoding masks are not coinciding. A structure of a system that looks promising to produce a like hologram and method of operation directly images a pattern, which is previously calculated by computer and displayed on the amplitude-phase mask is explained. The results obtained by numerical and experimental means are accompanied with a discussion about extents of this method.
Monitoring Passive optical Networks (PON) based on optical coding (OC) is a cost-effective monitoring technique. In a PON, the monitoring signals are transmitted on a dedicated band (U band) with data transmitted usin...
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ISBN:
(纸本)9781467393492
Monitoring Passive optical Networks (PON) based on optical coding (OC) is a cost-effective monitoring technique. In a PON, the monitoring signals are transmitted on a dedicated band (U band) with data transmitted using a different band (L-band). This paper introduces a new method to monitor Gigabit Passive optical Networks based on an OC technique. The proposed method utilizes the information from the PON ranging process that is managed by the optical Line Terminal to specify a fixed delay time for transmissions to and from the optical Network Units. The paper shows that information about the link status can be extracted from the decoded signal.
We demonstrate spectral coding in communication systems based on the use of refractive index dispersion of transparent optical materials. This approach to spectral coding is extremely simple and cheap and allows fibre...
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We demonstrate spectral coding in communication systems based on the use of refractive index dispersion of transparent optical materials. This approach to spectral coding is extremely simple and cheap and allows fibre or integrated devices to be realised.
This letter details an initial experimental demonstration of (de)coding of optical sequences coded in the two-dimensions of phase and wavelength through a pseudolocal oscillator. Narrow pulses at 1 Gb/s originating fr...
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This letter details an initial experimental demonstration of (de)coding of optical sequences coded in the two-dimensions of phase and wavelength through a pseudolocal oscillator. Narrow pulses at 1 Gb/s originating from a super-continuum (SC) fiber source with a specific frequency variation across their temporal width were, in addition, phase coded producing hybrid optical sequences. Successful decoding of the sequences using a pseudolocal oscillator in tandem with a coupler and balanced detector (coherent decoding) was accomplished. This approach to code formation allows access to a larger family of codes, potentially permitting more flexible network implementations based on optical code division principles.
We propose and demonstrate an all-optical analog-to-digital conversion system with a spatial coding method using a designed filter. To make available codes more flexible, the design technique for a computer-generated ...
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We propose and demonstrate an all-optical analog-to-digital conversion system with a spatial coding method using a designed filter. To make available codes more flexible, the design technique for a computer-generated hologram is introduced to our spatial coding scheme. By designing the spatial coding filter appropriately, this coding scheme enables us to output various digital signals as spatial patterns. By combining this coding method with the optical quantization method using soliton self-frequency shifting in a fiber, the proposed system converts analog sampled signals into arbitrary digital signals. Preliminary experimental results show that 3-bit Gray codes are successfully output as spatial patterns using the designed spatial coding filter.
The gray code based all-optical analog-to-digital conversion (ADC) using optical interconnection is described. Recent tremendous growths of optical communications and digital signal processing have encouraged the dema...
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ISBN:
(纸本)0819464481
The gray code based all-optical analog-to-digital conversion (ADC) using optical interconnection is described. Recent tremendous growths of optical communications and digital signal processing have encouraged the demand of high-speed and high-resolution ADC. To pursue a high-speed and high-resolution ADC, optical approaches have attracted much attention recently. ADC generally consists of three procedures: sampling, quantization and coding. Whereas the optical sampling techniques have been proposed and realized, the optical quantization and coding techniques have investigated depending on various applications. For the application to the binary detection of a high-speed digital signal, we previously proposed an all-optical ADC which consists of optical quantization using self-frequency shifting in a fiber and optical coding using optical interconnection for general binary code. In addition, since we can easily prepare optical interconnection patterns corresponding to the various codes, this technique can be used in any coding schemes. In this paper, we demonstrate the gray code based all-optical ADC to verify its scalability. Experimental results show that the 8-levels analog signals can be successfully converted into the bitwise allocated 3-bit gray code.
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