What is Passive Optical Network?

Passive Optical Network (PON) is a form of fiber-optic access network that uses point-to-multipoint fiber to the premises in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises. A PON system consists of an OLT at the service provider’s central office and a number of ONU units near end users, with an ODN between the OLT and ONU. PON reduces the amount of fiber and central office equipment required compared with point-to-point architectures.

PON Optical Network
Passive Optical Network (PON)

The most obvious advantage of the PON network is the elimination of the outdoor active devices. All the signals processing functions are completed in the switches and the user premises equipment. The upfront investment of this access methods are small, and the most funds investment is postponed until the user really access. Its transmission distance is shorter than the active optical access system. The coverage is also smaller, but it is low cost, no need to set the engine room, and easy to maintain. So this structure can be economically serve for the home users.

PON Development Background

Seen from the entire network structures, due to the larger numbers of laying optical fibers, and widely applications of DWDM technology, the backbone network has been a breakthrough in the development. The same time, due to advances in Ethernet technology, its dominant LAN bandwidth has increased from 10M, 100M to 1G or 10G.. At present, what we are concerned about is the part between the network backbone and local area networks, home users; this is often said that the “last mile”, which a bottleneck is. Must break this bottleneck, may user in the new world of the online world. It is as if in a national highway system, trunk and regional roads have been built in the broad high-grade highway, but leads to the families and businesses of the door was still narrow winding path, the efficiency of the road network cannot play.

What is OADM? How much do you know?

The OADM, or optical add drop multiplexer, is a aperture into and out of a distinct approach fiber. In practice, best signals canyon through the device, but some would be “dropped” by agreeable them from the line. Signals basic at that point can be “added” into the band and directed to addition destination. An OADM may be advised to be a specific blazon of optical cross-connect, broadly acclimated in amicableness analysis multiplexing systems for multiplexing and acquisition cilia optic signals. They selectively add and bead alone or sets of amicableness channels from a close amicableness analysis multiplexing (DWDM) multi-channel stream. OADMs are acclimated to bulk finer admission allotment of the bandwidth in the optical area actuality anesthetized through the in-line amplifiers with the minimum bulk of electronics.

OADM Module
CWDM and DWDM OADM

OADMs accept acquiescent and alive modes depending on the wavelength. In acquiescent OADM, the add and bead wavelengths are anchored advanced while in activating mode, OADM can be set to any amicableness afterwards installation. Acquiescent OADM uses Filter WDM, cilia gratings, and collapsed waveguides in networks with WDM systems. Activating OADM can baddest any amicableness by accessories on appeal after alteration its concrete configuration. It is additionally beneath big-ticket and added adjustable than acquiescent OADM. Activating OADM is afar into two generations.

A archetypal OADM consists of three stages: an optical demultiplexer, an optical multiplexer, and amid them a adjustment of reconfiguring the paths amid the optical demultiplexer, the optical multiplexer and a set of ports for abacus and bottomward signals. The optical demultiplexer separates wavelengths in an ascribe cilia assimilate ports. The reconfiguration can be accomplished by a cantankerous affix console or by optical switches which absolute the wavelengths to the optical multiplexer or to bead ports. The optical multiplexer multiplexes the amicableness channels that are to abide on from demultipexer ports with those from the add ports, assimilate a distinct achievement fiber.

Physically, there are several means to apprehend an OADM. There are arrays of demultiplexer and multiplexer technologies including attenuate blur filters, cilia Bragg gratings with optical circulators, changeless amplitude annoying accessories and chip collapsed arrayed waveguide gratings. The switching or reconfiguration functions ambit from the chital cilia application console to a array of switching technologies including micro-electro automated systems (MEMS), aqueous clear and thermo-optic switches in collapsed waveguide circuits.

CWDM and DWDM OADM accommodate abstracts admission for average arrangement accessories forth a aggregate optical media arrangement path. Regardless of the arrangement topology, OADM admission credibility acquiesce architecture adaptability to acquaint to locations forth the cilia path. CWDM OADM provides the adeptness to add or bead a distinct amicableness or multi-wavelengths from a absolutely multiplexed optical signal. This permits average locations amid alien sites to admission the common, point-to-point cilia bulletin bond them. Wavelengths not dropped pass-through the OADM and accumulate on in the administration of the alien site. Additional called wavelengths can be added or alone by alternating OADMS as needed.

DK Photonics provides a wide selection of specialized OADMs for WDM system. Compact CWDM module and custom WDM solutions are also available for applications beyond the current product designs including mixed combinations of CWDM and DWDM.

What is Pump Laser Protector, Where is the Pump Laser Protector use?

The Pump Laser Protector (also called Pump Protection Filters) is a passive component which allows maximum transmission from a discrete fibre-coupled pump laser diode and blocks parasitic signals around the centre wavelength of the laser from being reflected back into the laser.

Pump Laser Protector
Multimode Pump Laser Protector -10~30W

Single-emitter laser diodes are highly regarded for their long term reliability. However, these devices are very sensitive to backward propagating light within the delivery fiber. Backward power imaged onto the diode material, as small as 5% of the pump diode output, can cause accelerated diode degradation and, in the majority of cases, catastrophic failure.That is why we need Pump Laser Protector.

DK Photonics offers filter technology that provides protection to pump diodes under these conditions (up to 50 dB Backward Signal Attenuation). Splicing these filters to the pump output fiber rejects unwanted light before it reaches the diode.

Multimode Pump Protection filters are available for a wide range of standard light emitting diodes. Fiber pigtails are 105/125 micron, with both 0.15 and 0.22 NA cores and 50/125 or 62.5/126 MM fiber available. Operating wavelengths cover the majority of diode laser lines (915 nm, 940 nm, 960 nm and 976) and maximum power handling is 25W without water-cooling.DK Photonics recently released a new type of Pump Laser Protector up to 200W handling power with water-cooling technology. And also have SingleMode Pump Laser Protector with Hi1060 fiber for 976nm fiber laser.

If you do not see a Pump Laser Protector from the standard configurations that meets your needs, we welcome the opportunity to review your desired specification and quote a filter best suited to your application. Different pump/rejection wavelengths or fiber pigtail can be accommodated.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such asDK Photonics' promotion products including:High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

Introduction for CWDM MUX+DEMUX Module 8/16 Channels Dual Fiber with 1U 19 Rack Mount Box

Why do we choose CWDM MUX/DEMUX solution?

CWDM Mux/Demux is a flexible, low-cost solution that enables the expansion of existing fiber capacity. The CWDM Mux/Demux lets operators make full use of available fiber bandwidth in local loop and enterprise architectures. DK Photonics’ CWDM Mux/Demux is a universal device capable of combining up to 18 optical signals into a fiber pair or single fiber. It is designed to support a broad range of architectures, ranging from scalable point-to-point links to two fiber-protected rings. The important advantage of CWDM solution is the cost of the optics which is typically 1/3rd of the cost of the equivalent DWDM optics.

Description:

DK Photonics CWDM MUX+DEMUX Module 8/16 Channels (Dual Fiber) with 1U 19 Rack Mount Box utilize thin film coating technology and proprietary design of non-flux metal bonding micro optics packaging. Our 8CH CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box support ITU-T G.694.2 wavelengths between 1270nm to 1610nm in 20nm increments. (Note: The ITU standard specifies the exact center of 8/16CH CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box wavelength as 1531nm, 1591nm, 1611nm, etc. However, for clarity (and to comply with general industry conventions) the text in this data sheet refers to these wavelengths as 1530nm, 1590nm, 1610nm, etc.) 8/16 Channel CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box are protocol and rate transparent allowing different services up to 10Gbps to be transported across the same fiber link. It allows for any protocol to be transported over the link, as long as it is at a specific wavelength (i.e. T1 over fiber at 1570nm transported alongside 10Gbps Ethernet at 1590nm). This allows for long-term future proofing of the networking infrastructure because the multiplexers simply refract light at any network speed, regardless of the protocol being deployed.

Our CWDM Mux/Demux can support up to 18 wavelengths between 1270nm to 1610nm in 20nm increments when com fiber is ITU-T G.694.2 , however if com fiber is ITU-T G.652, we recommend adopt 1270nm and 1290nm instead of 1390nm and 1509nm because of water peak loss.

DK Photonics’ provides a complete portfolio of CWDM Mux Demux and Optical Add Drop Multiplexer (OADM) units to suit all applications such as:- Gigabit & 10G Ethernet, SDH/SONET, ATM, ESCON, Fibre Channel, FTTx and CATV.

8/16 channel CWDM MUX+DEMUX in point to point application
8/16 channel CWDM MUX+DEMUX in point to point application

Key Features

  • Up to 18 channels over 2 fibers
  • MUX and DEMUX combined 1U
  • Optical interfaces support all protocols from 30Mbps to 10Gbps, including OC-3/STM-1, OC-12/STM-4, OC-48/STM-16, OC-192/STM-64, Gigabit Ethernet SX, Gigabit Ethernet LX, Fast Ethernet, FDDI, ATM, ESCON, FICON, Fiber Channel, Coupling Link, 10G Ethernet
  • Distance up to 120km, based on used CWDM SFP+, CWDM XFP, CWDM X2, CWDM XENPAK, CWDM SFP, CWDM GBIC transceivers
  • Any configuration on demand
  • Your choice of adapter: SC, LC, E2000, MU etc
  • 19” 1U size or other according to customer requirements
  • For Central Office or Outside Plant
  • Compliant to ITU-T G.694.2 CWDM standard
  • ISO 9001 manufacturing facility
  • Fully transparent at all data rates and protocols from T1 to 40 Gbps
  • Completely passive, no power supply needed
  • Simple to install, requires no configuration or maintenance
  • Low-cost transceivers applicable, existing equipment can still be used

Applications

  • All Enterprises and Carrier with Fiber Optic Infrastructure
  • Transmit additional applications via existing lines
  • Connect buildings to CWDM campus ring
  • Connect Field offices to central office
  • Ideal solution for metro-core, metro-access and enterprises

DK Photonics’ 1RU Rack-mount chassis are made by best which can protect CWDM MUX/DEMUX inside well. These Low profile modular designs are widely used in computer centers, center office, IDC, OLT and FDC etc.

Introduction to CWDM Technology

CWDM (Coarse Wavelength Division Multiplexing) is a technology which multiplexes multiple optical signals on one fiber optic strand by making use of different wavelengths, or colors, of laser light to hold different signals. CWDM technology uses ITU standard 20nm spacing within the wavelengths, from 1270nm to 1610nm.

16CH CWDM Mux Module
16CH CWDM Mux Module

CWDM In comparison with DWDM

Accordingly, they’ve got two important characteristics built into systems employing CWDM optical components which permit easier and for that reason also less expensive than in DWDM systems. CWDM is very easy in terms of network design, implementation, and operation. CWDM works together few parameters that want optimization from the user, while DWDM systems require complex calculations of balance of power per channel, which is further complicated when channels are added and removed or when it’s utilized in DWDM networks ring, particularly if systems incorporate optical amplifiers.

 

CWDM Function

CWDM modules perform two functions. First, they filter the lighting, ensuring only the desired wavelengths are used. Second, they multiplex or demultiplex multiple wavelengths, which are put on just one fiber link. The real difference is in the wavelengths, which might be used. In CWDM space, the 1310-band as well as the 1550-band are broken into smaller bands, each only 20-nm wide. Inside multiplex operation, the multiple wavelength bands are combined onto just one fiber. Within the demultiplex operation, the multiple wavelength bands are separated from one fiber.

Generally, a CWDM network takes two forms. A point-to-point system connects two locations, muxing and demuxing multiple signals for a passing fancy fiber. A loop or multi-point system connects multiple locations, typically using Add/Drop modules.

 

CWDM Modules Types

CWDM Modules utilize thin-film coating and micro optics package technology. CWDM modules consider two main configurations: CWDM Multiplexer/Demultiplexer (CWDM Demux) modules and CWDM Add/Drop Multiplexer (CWDM OADM) modules.

Mux products will include a few statistics symptoms in a only for having using a one-time fabric. Demux isolate all of the symptoms inside various terminate. Any value reaches an extra wavelength.

CWDM Mux/demux are created to multiplex multiple CWDM channels into One or two fibers. Within a hybrid configuration (mux/demux), multiple transmit and receive signals can be combined onto a single fiber. Each signal is assigned a different wavelength. At each and every end, transmit signals are muxed, while receive signals are demuxed. CWDM Mux/demux can be a flexible plug-and-play network solution, allowing carriers and enterprise companies to cheaply implement examine point or ring based WDM optical networks. CWDM Mux/demux is modular, scalable and it’s perfectly suited to transport PDH, SDH / SONET, ETHERNET services over WWDM, CWDM and DWDM in optical metro edge and access networks.

The most popular configuration of CWDM mux/demux is 2CH, 4CH, 5CH, 8CH, 9CH, 16CH and 18CH CWDM MUX/DEMUX. and also Compact CWDM module, 3 Single fiber or dual fiber connection for CWDM Mux/demux can also be found. These modules passively multiplex the optical signal outputs from 4 or higher electronics, send to them merely one optical fiber and then de-multiplex the signals into separate, distinct signals for input into technology along at the opposite end in the fiber optic link.

More information about CWDM: WDM Products

DK Photobics Released Compact CWDM(Mini CWDM) Module

Shenzhen,China,September 10,2013 – DK Photonics recently released ompact CWDM(Mini CWDM) Module.

DK Photonics now can offers a Mini CWDM (compact CWDM) module that provides bandwidth capacity expansion for future network growth in one of the industry’s smallest packages.The compact CWDM modules are based on free space optics technology.It is available in 4-or 8-channel configurations.It have lower overall insertion loss and better uniformity across the channels.Its compact size and unique carrier tray set it apart, making it easier to deploy in a variety of field situations.

The Compact CWDM module comes with a carrier that allows for fast and easy snap-in mounting to splice tray or closure. Key benefits: -Compact size: (L)53.8x(W)28x(H)8 mm. -Free Space Optics design: Lower overall insertion loss and better uniformity across the channels. -Simplified inventory management: The same component can be used in the head end or outside plant and as a Mux or Demux.

About DK Photonics DK Photonics has been a well-established specialized fiber optic component supplier for fiber optic telecommunication,fiber lasers and fiber sensor applications in those years. We have excellent engineering capability, a well-established manufacturing process, and a high-quality standard.DK Photonics’ promotion products including:1064nm High Power Isolator,1064nm Components, PM Components, (2+1)X1 Pump Combiner,Pump Laser Protector,Mini-size CWDM,100GHz DWDM,Optical Circulator,PM Circulator,PM Isolator,Fused Coupler,Mini Size Fused WDM.

You are most welcome to contact DK Photonics(www.dkphotonics.com) to explore a wide range of promising business opportunities.