Space product aggregates, components and parts of optical instruments
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Modern manufacturing is being revolutionized by the use of optics, which can both improve current manufacturing capabilities and enable new ones. Light can be used to process or probe materials remotely, even through windows isolating harsh or vacuum environments. With no surface contact, there is no contamination of the process by the probe beam and no wear of tool edges. Scanning provides action over large areas.VIDEO ON THE TOPIC: Optical Instruments
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100G Metro Network
A passive optical network PON is a fiber-optic telecommunications technology for delivering broadband network access to end-customers. Its architecture implements a point-to-multipoint topology, in which a single optical fiber serves multiple endpoints by using unpowered passive fiber optic splitters to divide the fiber bandwidth among multiple access points. Passive optical networks are often referred to as the " last mile " between an Internet service provider ISP and its customers. A passive optical network consists of an optical line terminal OLT at the service provider's central office hub and a number of optical network units ONUs or optical network terminals ONTs , near end users.
A PON reduces the amount of fiber and central office equipment required compared with point-to-point architectures. A passive optical network is a form of fiber-optic access network. In most cases, downstream signals are broadcast to all premises sharing multiple fibers. Encryption can prevent eavesdropping. Upstream signals are combined using a multiple access protocol, usually time division multiple access TDMA.
Starting in , work on fiber to the home architectures was done by the Full Service Access Network FSAN working group, formed by major telecommunications service providers and system vendors. Again, the standards permit several choices of bit rate, but the industry has converged on 2.
By mid, Verizon had installed over , lines. The chief information officer of the United States Department of the Army issued a directive to adopt the technology by fiscal year It is marketed to the US military by companies such as Telos Corporation.
EPON is a "short haul" network using ethernet packets, fiber optic cables, and single protocol layer. EPON is applicable for data-centric networks, as well as full-service voice, data and video networks. The upstream channel can support simultaneous operation of IEEE This technology connects seamlessly with any type of IP-based or packetized communications, and, thanks to the ubiquity of Ethernet installations in homes, workplaces, and elsewhere, EPON is generally very inexpensive to implement.
As with bit rate, the standards describe several optical power budgets , most common is 28 dB of loss budget for both BPON and GPON, but products have been announced using less expensive optics as well.
In multiple-tenant units, the ONU may be bridged to a customer premises device within the individual dwelling unit using technologies such as Ethernet over twisted pair, G. Some ONUs implement a separate subscriber unit to provide services such as telephony, Ethernet data, or video. These typically include:.
Often the ONU functions are separated into two parts:. Each ONU reads the content of only those packets that are addressed to it. Encryption is used to prevent eavesdropping on downstream traffic. Because the optical distribution network ODN is shared, ONU upstream transmissions could collide if they were transmitted at random times.
A grant is permission to use a defined interval of time for upstream transmission. The grant map is dynamically re-calculated every few milliseconds. Some services — POTS , for example — require essentially constant upstream bandwidth, and the OLT may provide a fixed bandwidth allocation to each such service that has been provisioned. DS1 and some classes of data service may also require constant upstream bit rate.
But much data traffic, such as browsing web sites, is bursty and highly variable. Through dynamic bandwidth allocation DBA , a PON can be oversubscribed for upstream traffic, according to the traffic engineering concepts of statistical multiplexing. Downstream traffic can also be oversubscribed, in the same way that any LAN can be oversubscribed. The only special feature in the PON architecture for downstream oversubscription is the fact that the ONU must be able to accept completely arbitrary downstream time slots, both in time and in size.
If the ONU has no traffic to send, it transmits idle frames during its excess allocation. In the upstream direction, each ONU optical network units or ONT optical network terminal burst transmits for an assigned time-slot multiplexed in the time domain. In the downstream direction, the OLT usually continuously transmits or may burst transmit. Radio frequency over glass RFoG is a type of passive optical network that transports RF signals that were formerly transported over copper principally over a hybrid fibre-coaxial cable over PON.
RFoG offers backwards compatibility with existing RF modulation technology, but offers no additional bandwidth for RF based services. Although not yet completed, the RFoG standard is actually a collection of standardized options which are not compatible with each other they cannot be mixed on the same PON.
Some of the standards may interoperate with other PONs, others may not. It offers a means to support RF technologies in locations where only fiber is available or where copper is not permitted or feasible.
Alternatively the wavelengths can be used collectively through statistical multiplexing to provide efficient wavelength utilization and lower delays experienced by the ONUs. PONs provide higher bandwidth than traditional copper based access networks.
Challenges : High cost of initial set-up, the cost of the WDM components. Temperature control is another challenge because of how wavelengths tend to drift with environmental temperatures. Work by Davey and Payne at BT showed that significant cost savings could be made by reducing the electronic equipment and real-estate required at the local exchange or wire center. This technology has sometimes been termed Long-Reach PON, however, many argue that the term PON is no longer applicable as, in most instances, only the distribution remains passive.
For the downstream transmission, the OLT broadcasts optical signal to all the ONUs in continuous mode CM , that is, the downstream channel always has optical data signal.
Use of CM would result in all of the signals transmitted from the ONUs converging with attenuation into one fiber by the power splitter serving as power coupler , and overlapping. To solve this problem, burst mode BM transmission is adopted for upstream channel. The given ONU only transmits optical packet when it is allocated a time slot and it needs to transmit, and all the ONUs share the upstream channel in the time division multiplexing TDM mode. In order to compensate the phase variation and amplitude variation in a short time for example within 40 ns for GPON  , burst mode clock and data recovery BM-CDR and burst mode amplifier for example burst mode TIA need to be employed, respectively.
Furthermore, the BM transmission mode requires the transmitter to work in burst mode. Such a burst mode transmitter is able to turn on and off in short time. The above three kinds of circuitries in PON are quite different from their counterparts in the point-to-point continuous mode optical communication link. Passive optical networks do not use electrically powered components to split the signal. Instead, the signal is distributed using beam splitters.
Each splitter typically splits the signal from a single fiber into 16, 32, or up to fibers, depending on the manufacturer, and several splitters can be aggregated in a single cabinet. A beam splitter cannot provide any switching or buffering capabilities and does not use any power supply; the resulting connection is called a point-to-multipoint link.
For such a connection, the optical network terminals on the customer's end must perform some special functions which would not otherwise be required. For example, due to the absence of switching, each signal leaving the central office must be broadcast to all users served by that splitter including to those for whom the signal is not intended.
It is therefore up to the optical network terminal to filter out any signals intended for other customers. In addition, since splitters have no buffering, each individual optical network terminal must be coordinated in a multiplexing scheme to prevent signals sent by customers from colliding with each other.
Two types of multiplexing are possible for achieving this: wavelength-division multiplexing and time-division multiplexing. With wavelength-division multiplexing, each customer transmits their signal using a unique wavelength. With time-division multiplexing TDM , the customers "take turns" transmitting information. TDM equipment has been on the market longest. Passive optical networks have both advantages and disadvantages over active networks.
They avoid the complexities involved in keeping electronic equipment operating outdoors. They also allow for analog broadcasts, which can simplify the delivery of analog television. However, because each signal must be pushed out to everyone served by the splitter rather than to just a single switching device , the central office must be equipped with a particularly powerful piece of transmitting equipment called an optical line terminal OLT. In addition, because each customer's optical network terminal must transmit all the way to the central office rather than to just the nearest switching device , reach extenders would be needed to achieve the distance from central office that is possible with outside plant based active optical networks.
The drivers behind the modern passive optical network are high reliability, low cost, and passive functionality. Proposed requirements for these components were published in by Telcordia Technologies.
The broad variety of passive optical components applications include multichannel transmission, distribution, optical taps for monitoring, pump combiners for fiber amplifiers, bit-rate limiters, optical connects, route diversity, polarization diversity, interferometers, and coherent communication.
WDMs are optical components in which power is split or combined based on the wavelength composition of the optical signal. Wavelength insensitive couplers are passive optical components in which power is split or combined independently of the wavelength composition of the optical signal.
A given component may combine and divide optical signals simultaneously, as in bidirectional duplex transmission over a single fiber.
Passive optical components are data format transparent, combining and dividing optical power in some predetermined ratio coupling ratio regardless of the information content of the signals.
WDMs can be thought of as wavelength splitters and combiners. Wavelength insensitive couplers can be thought of as power splitters and combiners. An optical isolator is a two-port passive component that allows light in a given wavelength range to pass through with low attenuation in one direction, while isolating providing a high attenuation for light propagating in the reverse direction. Isolators are used as both integral and in-line components in laser diode modules and optical amplifiers, and to reduce noise caused by multi-path reflection in high-bitrate and analog transmission systems.
An optical circulator operates in a similar way to an optical isolator, except that the reverse propagating lightwave is directed to a third port for output, instead of being lost. An optical circulator can be used for bidirectional transmission, as a type of branching component that distributes and isolates optical power among fibers, based on the direction of the lightwave propagation.
Fiber optic filters are in-line, wavelength selective, components that allow a specific range of wavelengths to pass through or reflect with low attenuation for classification of filter types.
From Wikipedia, the free encyclopedia. Telecommunications technology used to provide fiber to the end consumer. Main article: Fiber to the x. FSAN Group official web site.
Archived from the original on October 12, Retrieved September 1, Archived from the original on Retrieved October 2, Archived from the original PDF on Retrieved Global Industry Analysts Inc. BT Technology Journal.
Passive Optical LAN
XR optics is engineered to break the inherent limitations of traditional point-to-point optical transmission solutions and paves the way for disruptive network economics and a paradigm shift in transport architectures. Powered by independently routable Nyquist subcarriers and coherent optical aggregation capabilities, XR optics will enable network operators to design more efficient, flexible, and costeffective transport networks optimized for the applications driving network growth. Connections in optical transport networks have historically been implemented using point-topoint technology, which requires matching transceivers of identical speed on each end of the fiber link. These point-to-point solutions are extremely inefficient at handling hub-and-spoke traffic flows, which dominate traffic patterns in aggregation networks. In addition, as networks scale, additional digital aggregation devices are required at intermediate locations to support the conversion to higher speeds.
By month By size and duration 6. Involving workers or more 7. Involving workers or more beginning in 8. By industry group and size
Space & Scientific Instrumentation: earth observation, laser-satellite communication, astronomy
OJ L , In force: This act has been changed. Since further amendments are to be made, it should be recast in the interests of clarity. An effective common system of export controls on dual-use items is necessary to ensure that the international commitments and responsibilities of the Member States, especially regarding non-proliferation, and of the European Union EU , are complied with. The existence of a common control system and harmonised policies for enforcement and monitoring in all Member States is a prerequisite for establishing the free movement of dual-use items inside the Community. Decisions to update the common list of dual-use items subject to export controls must be in conformity with the obligations and commitments that Member States have accepted as members of the relevant international non-proliferation regimes and export control arrangements, or by ratification of relevant international treaties. Common lists of dual-use items, destinations and guidelines are essential elements for an effective export control regime.
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XR optics is a revolutionary technology purpose-built to break the inherent limitations of traditional point-to-point optical transmission solutions. XR optics paves the way for disruptive network economics as 5G, fiber deep, and hyperscale cloud connectivity impose new challenges on operators. With game-changing innovation in coherent optical subcarrier aggregation, XR optics introduces a new pluggable and software-enabled architecture designed to radically reduce the cost of deploying and operating optical networks. Since the inception of optical networking, there has been a significant misalignment between actual traffic patterns and the technology used to transport that traffic. Network traffic patterns, particularly in metro networks, are overwhelmingly hub and spoke — i.
Optics , science concerned with the genesis and propagation of light , the changes that it undergoes and produces, and other phenomena closely associated with it. There are two major branches of optics, physical and geometrical. Physical optics deals primarily with the nature and properties of light itself.
Products and Services
The more complex your network becomes, the more challenging it is to know which products to use, how to integrate them, how to budget for them, and how to ensure your network runs with zero downtime. In addition to providing an extensive Passive Optical LAN product set, our team can assist you in building the ideal solution for your specific POL challenge. This architecture is based upon carrier-grade passive optical network technology that has been reliably utilized in fiber-to-the-home deployments for many years. The OLT is normally located in the equipment room and aggregates optical traffic and provides the interface to edge IP network switches and routers.
US Conec, a global leader in the design and development of high-density optical interconnects, unveils a revolutionary new duplex optical connector solution: the MDC connector. The MDC is a two fiber connector manufactured with proven 1. Three port MDC adapters fit directly into standard panel openings for duplex LC adapters increasing fiber density by a factor of three. Supporting port breakout architectures for emerging transceiver MSAs, the smaller size will allow a single array transceiver to accept multiple MDC patch cables which are individually accessible directly at the transceiver interface. Insertion and extraction of the MDC connector occurs with a simple push or pull on a flexible and robust strain relief boot providing functional density in very tight spaces.
EUR-Lex Access to European Union law
The focus is on high-resolution spatial and spectral systems. In addition to complete systems, focal planes and optical components to be investigated. It focuses on the performance analysis, and radiometric and geometric calibration of optical sensors. Performance parameters e. The radiometric calibration allows converting digital values from the optical system into physical units of radiance. By means of the geometric calibration the viewing angle in the object space are determined for each pixel.
TNO cooperates with companies, the public sector and other organisations, to apply our knowledge and expertise with and for others. TNO offers you the chance to do groundbreaking work and help customers and society with innovative, practical and smart solutions. On TNO Insights you can read in-depth interviews and articles. From ground-breaking climate research and satellites for observational systems, to non-invasive medical research and semiconductor production: we have a lot to thank optical scientific instruments for, including their use in space technology.
Infinera Debuts Component for Coherent Subcarrier Aggregation
I, Marise Payne, Minister for Defence, make the following instrument. Marise Payne. Any other statement in column 2 has effect according to its terms. It will not be amended to deal with any later amendments of this instrument.
Here we provide an overview of major C6 optical property algorithm changes relative to the previous Collection 5 C5 product. Notable C6 optical and microphysical algorithm changes include: i new ice cloud optical property models and a more extensive cloud radiative transfer code lookup table LUT approach, ii improvement in the skill of the shortwave-derived cloud thermodynamic phase, iii separate cloud effective radius retrieval datasets for each spectral combination used in previous collections, iv separate retrievals for partly cloudy pixels and those associated with cloud edges, v failure metrics that provide diagnostic information for pixels having observations that fall outside the LUT solution space, and vi enhanced pixel-level retrieval uncertainty calculations. Example Level-2 granule and Level-3 gridded dataset differences between the two collections are shown. While the emphasis is on the suite of cloud optical property datasets, other MODIS cloud datasets are discussed when relevant.
Не может быть! - сказала она по-испански. У Беккера застрял комок в горле. Росио была куда смелее своего клиента. - Не может быть? - повторил он, сохраняя ледяной тон. - Может, пройдем, чтобы я смог вам это доказать.
Никто не сомневался, что АНБ проиграло сражение. Цель была достигнута. Все глобальное электронное сообщество было обведено вокруг пальца… или так только. ГЛАВА 5 Куда все подевались? - думала Сьюзан, идя по пустому помещению шифровалки. - Ничего себе чрезвычайная ситуация. Хотя большинство отделов АНБ работали в полном составе семь дней в неделю, по субботам в шифровалке было тихо. По своей природе математики-криптографы - неисправимые трудоголики, поэтому существовало неписаное правило, что по субботам они отдыхают, если только не случается нечто непредвиденное.
Стратмор поднял брови. - Целых три часа. Так долго.