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Two AOD variable optical attenuator As one can see the +fc frequency shift at the first AOD is cancelled by the-fc shift at the second. In this way the frequency of the incident laser beam do not change. The above set up, proposed early by other authors, use two
Source publication
A novel variable optical attenuator device is proposed and some of the potential application is
pointed out. It relies on a double acousto - optic modulator set up and allows one to
attain dynamic range as high as 60 dB. Such feature steams out of the well known modeling of
acousto - optic devices, mostly based on the coupled wave analysis. Further...
Contexts in source publication
Context 1
... first set up designed to be a variable optical attenuator is displayed on Figure 2. It is based on two AOM [6]. ...
Context 2
... the access time depends on the point the laser incident beam reach the ultrasound wave inside the crystalline block. It could be as small as possible if one reduces the equivalent distance to x1+x2 at the Figure 2. With such characteristics the access time can be of the same order of the first set up, sub-microseconds. ...
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Citations
... The insertion loss of each branch in such a splitter also depends on the wavelength of the transmitted optical signal. The implementation (construction) of the tunable optical splitter is usually more difficult and this type of splitter typically requires an external power source for its operation; hence, they are no longer passive [10], [11]. ...
... The next section presents the specific calculations and comparisons based on Equations (8), (9), (11) and (12), and it brings the solutions by using standard splitters with uniform splitting ratio (50/50%), splitters with individually optimized splitting ratios and splitters with standardized series of splitting ratio from [12]. ...
Passive optical networks (PONs) represent a promising solution for modern access telecommunication networks. These networks are able to meet the increasing demands on transmission rate for demanding multimedia services, while they can offer typical shared transmission speed of 1.25 or 2.5 Gbps. The major role in deploying optical distribution networks ODNs plays the maximum attenuable loss, which is caused mainly by passive optical splitters. This paper proposes an innovative application of passive optical networks with optimized bus topology especially for local backbone data networks. Due to using only passive components, it is necessary to optimize certain parameters, especially an overall attenuation balance. Considering the possibility of such optimization, the passive optical network with optimized bus topology provides several interesting opportunities for specific applications. This paper will present selected aspects of passive optical networks and splitters with asymmetric splitting ratio. The essential part is focused on the practical demonstration of their use to optimize the passive optical network with bus topology, which acts as a local backbone network for structured cabling systems, and for local data networks in large buildings.
The standing balance measurement system for the center of gravity of the human body using fiber Bragg gratings (FBGs) is proposed in this paper. The measurement platform is used to measure the center of gravity of the human body in order to diagnose if a patient has a balance or related disorder as well as the severity. The system obtains parameters of the patient such as distance and area by measuring the center of gravity shake that induces stress signals to bend FBG sensor. Wavelength shift of the FBG is detected, and this signal is used to display a center of gravity trajectory figure on a computer screen. Medical database and these data can be used to determine whether the patient suffers from a balance-related disease and provides the best method for treatment. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2355–2359, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26267
This paper proposes an innovative application of passive optical networks with optimized bus topology for local backbone data networks. Passive optical networks represent a promising solution for modern access networks to meet the increasing demands on transmission rate for demanding multimedia services. As these networks rely exclusively on passive components implemented in their entire infrastructure, it is necessary to consider their certain specific features and optimize properly necessary parameters, especially an attenuation balance. Considering the possibility of such optimization, the passive optical network with optimized bus topology provides several interesting opportunities for specific applications. Its potential application is, for example, a high-speed local backbone infrastructure connecting local data switches and routers. For that purpose, the passive optical splitter with adjustable power splitting ratio at its outputs can be used for the optimization process of attenuation balance. This paper presents a mathematical apparatus for calculating the maximum number of splits and the number of bridge taps in the passive optical network with the bus topology and an example of obtained results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2351–2355, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26291
