Search Results for 'wdm'

[Hamza Ali Abbas KhanParticipant]

Hi Karan ahuja
Here i would like to share advantage and disadvantage of EDFA:
High power transfer efficiency from pump to signal power (> 50%) , Wide spectral band amplification with relative flat gain (>20 dB) – useful for WDM applications, Saturation output > 1 mW (10 to 25 dBm) , Gain-time constant long (>100 msec) to overcome patterning effects and inter-modulation , distortions ( low noise) , Large dynamic range , Low noise figure , Polarization independent and Suitable for long-haul applications.
Disadvantages of EDFAs:
Relatively large devices (km lengths of fiber) – not easily integrated with other
devices , ASE – amplified spontaneous emission. There is always some output even with no signal input due to some excitation of ions in the fiber – spontaneous noise, Cross-talk effects and Gain saturation effects.
I hope this will help
Thanks

[Hamza Ali Abbas KhanParticipant]

Hi,
Fiber amplifiers used in WDM systems usually make use of control systems as power or gain. Designs Er-doped fiber amplifiers by considering numerical solutions of the rate and the propagation equations under stationary conditions. The model includes amplified spontaneous emission (ASE) as observed in the amplifier Erbium Doped Fiber.
The main difference is related to the amplifier pump scheme selection. You can choose co-propagating, counter-propagating, or bi-directional pump schemes with the option to set wavelength and pump power. Geometrical Er-doped fiber parameters and cross-section curves are required as input files. As output files, you can access gain, output power values, and noise figure determined in the ASE bandwidth set as noise input data.
Enables the design of amplifiers, including EDFAs, that consider pre-defined operational conditions. This means that expected gain, noise figure, and amplifier output power can be previously specified. The amplifier presents the same facilities as a black box model, which enables you to select the operation mode with gain control, power control, or to perform simulations under saturated conditions, as well as define the expected amplifier performance. It is specially suited to perform prompt performance analysis of one or cascaded amplifiers in a long-haul system.

Hope this helps.
Thanks

[Rajguru M. MohanParticipant]

Hi,

As, FSO is a line-of-sight technology that uses invisible beams of light to provide optical bandwidth connections that can send and receive voice, video, and data information.
In today’s, FSO technology — the foundation of Light Pointe’s optical wireless offerings — has enabled the development of a new category of outdoor wireless products that can transmit voice, data, and video at bandwidths up to 1.25 Gbps.
This optical connectivity doesn’t require expensive fiber-optic cable or securing spectrum licenses for radio frequency (RF) solutions. FSO technology requires light. The use of light is a simple concept similar to optical transmissions using fiber-optic cables;
the only difference is the medium. Light travels through air faster than it does through glass, so it is fair to classify FSO technology as optical communications at the speed of light.
While fiber-optic communications gained worldwide acceptance in the telecommunications industry, FSO communications is still considered relatively new. FSO technology enables bandwidth transmission capabilities that are similar to fiber optics, using similar optical transmitters and receivers and even enabling WDM-like technologies to operate through free space.

Thanks,

[Hoat Le]

Hi everybody. I am researching energy-saving solutions for OFDM-WDMPON network. What is solutions for the energy saving at the OLT ? thank you !

[Hoat Le]

Hi everybody . I am researching energy-saving solutions for OFDM-WDMPON network. What is the solutions for energy-saving at the OLT ? thank you !

[Hermawan Widiyanto]

Hello, i have a bit problem that i want to ask during using optisystem. I created a project about DWDM within 32 channels, in the end of scheme, i use BER analyzer as an visualizer. Now the problem is, how can i export these data of my visualizers to excel spreadsheet or if is not, can i save all of visualizers data include Q factor values to another type file? there’s any script or command to realize that? i hope you can sharing about your experiences using optisystem to overcome this problem.

thanks,
regards

[Rajguru M. MohanParticipant]

Hi AAsif,
Although we have three dispersion compensation techniques namely pre, post and symmetrical.
I like to add basic elements and parameters of dispersion compensation :
Fiber Bragg gratings (FBG) are one of the important methods of
dispersion compensation. They reflect different frequencies from
different length, at the end, different frequency components of the
signal will see different phase delays. They have short length (~10-
15cm). They are not very suitable for WDM applications because
of their narrow bandwidth (~0.1-5nm). They have very low loss
like 1dB in 80km. Their short length provides less nonlinear
operation.
Dispersion-compensating fibers (DCF) are another important
method of dispersion compensation. They operate by insertion of
fibers with dispersion of negative slope, high absolute value. Their
lengths can be 17-20km. Lengths are too high that nonlinear
effects cause a problem. They have wide bandwidth suitable for
WDM applications (~20nm).

Thanks,

[Rajguru M. MohanParticipant]

Hi Eoin,
I like to discuss some of features and applications of a 1270 nm- 1610nm Series 18 Channels CWDM Laser Diode Modules:
FEATURES

Un-cooled 1270 nm – 1610nm DFB laser diode (LD) with MQW structure

High temperature operation without active cooling

Hermetically sealed active component

Single frequency operation with high side mode suppression ratio

Build-in high performance/speed InGaAs monitor PIN photodiode (PD)

For 9/125 mm SM fiber

PACKAGING

Fiber pigtailed with optional FC/ST/SC connector

Packaged in FC or ST Receptacle with fiber stub.

APPLICATIONS

Design for CWDM fiber optic networks

SONET OC-12/OC-48 / SDH /STM-4/STM-16

Gigabit Ethernet

Stable emitting source at specific wavelength

Thanks,

[Rajguru M. MohanParticipant]

Hi Ankita,

A PON system utilizes a passive splitter that takes one input and splits it to “broadcast” signals downstream to many users. This reduces the cost of the system substantially by sharing one set of electronics and an expensive laser with up to 32 homes. Upstream, the passive splitter acts as a combiner to connect all users to the same shared PON port. An inexpensive laser is used for the home to send signals back to the FTTH system in the central office.
Different technologies of GPON are:
BPON, or broadband PON, was the most popular PON application in the beginning. BPON uses ATM as the protocol. ATM is widely used for telephone networks and the methods of transporting all data types (voice, Internet, video, etc.) are well known. BPON digital signals operate at ATM rates of 155, 622 and 1244 Mb/s.
Downstream digital signals from the CO through the splitter to the home are sent at 1490 nm. This signal carries both voice and data to the home. Video on the first systems used the same technology as CATV, an analog modulated signal, broadcast separately using a 1550 nm laser which may require a fiber amplifier to provide enough signal strength to overcome the loss of the optical splitter. Video could be upgraded to digital using IPTV, negating the need for the separate wavelength for video. Upstream digital signals for voice and data are sent back to the CO from the home using an inexpensive 1310 nm laser. WDM couplers separate the signals at both the home and the CO.

Thanks,

[love kumarParticipant]

hi all thanks for your concerns and devoting tour time to solve me issue .. i agree with all ho you no direct method is there to measure the crosstalk in opti system .. do anyone aware about mathematical relation of signal power and crosstalk for DWDM system … it will be very helpful for me

[Rajguru M. MohanParticipant]

Hi,
As Optical circulators are important components in optical fiber communication.
Optical circulators can be used to achieve bi-directional optical signal transmission over a single fiber. Optical circulators is commonly used in WDM networks, polarization mode dispersion, chromatic dispersion compensation, optical add-drop modules (DWDM OADM), optical amplifiers, OTDR and fiber sensing applications. Fiberstore offer 3/4 ports polarization-insensitive optical circulator and 1310/1550/1064 polarization-maintaining (PM) optic circulators. Our fiber optical circulators can provide high isolation, very low insertion loss, low polarization dependent loss (PDL), low polarization mode dispersion (PMD), and excellent environmental stability. Any other wavelengths, without or with any connector can customized according to your requirement.

Thanks,

[Rajguru M. MohanParticipant]

Hi Ranjeet,
ptical Circulators are non-reciprocating, one-directional, three port devices which are great for bidirectional propagation
of light in a single fiber.In fiber optical networks passive components such as optical isolators are essential for delivering of signals with minimum loss. Another type of passive element that is commonly used in fiber optic systems is the optical circulator. These devices that are used to direct the optical signal from one port to another port and in one direction only. This action prevents the signal from propagating in an unintended direction. Optical circulators have continued to increase their presence in a broad array of applications, including optical amplifiers, optical add and drop systems, dense wavelength-division multiplexing (DWDM Mux) networks and, optical time domain reflectometers (OTDRs).n a 3-port circulator a signal is transmitted from port 1 to port 2, another signal is transmitted from port 2 to port 3 and, finally, a third signal can be transmitted from port 3 to port 1. The name derives from the fact that a signal is transmitted from Port 1 to Port 2, another signal can be transmitted from Port 2 to Port 3 and, finally, a signal can be transmitted from Port 3 to Port 1. In practice, one or two ports are used as inputs and the third port is used as the output.

Thanks,

[Eoin Kavanagh]

Hi all,

I’m currently doing a college project on modelling a typical low end 2.5 G CWDM laser with a output power of 0 dBm and line width of 1 nm.
The laser is drifting towards the adjacent channel but do the CW lasers provide an accurate representation of a typical CWDM laser? Thanks.

[Aabid BabaParticipant]

Hello Love Kumar,
As far as your query is concerned i don’t think there is a way to calculate the crosstalk directly in optisystem. As such i have not found any component in the optisystem component library that could be used to measure crosstalk of any system that we design here. However, there are certain .osd files where there is mentioned something regarding crosstalk in a design. As mentioned by Hamza Ali Abbas Khan , you can refer to the link where there is a WDM ring architecture which you may find useful . For your convenience i will repost the link below. Try to refer to it and i hope you will get some idea about it.

Interchannel Crosstalk in Metro Networks

Regards

[Hamza Ali Abbas KhanParticipant]

A particular signal can accumulate cross-talk from different elements and channels over the network. Cross-talk can be reduced by using several techniques such as wavelength dilation or filter cascading. In this example, we will investigate the effect of interchannel cross-talk at ADM to a ring network. The project is found in the Interchannel crosstalk at ADM in a ring network.osd file. This network contains 4 nodes that communicate over two channels at 193 THz and 193.1 THz. The bit rate is 10 Gbps. ADMs at each node is modeled by using WDM add and WDM drop components. WDM add and drop components are created by using 4th order Bessel filters. The ring is ended with a ring control component which can circulate the signals around ring for a given number of times. The distance between nodes is 12.5 km and we inserted an ideal amplifier just before node 2 to compensate for the total fiber loss in the ring. Dispersion and nonlinear effects of fibers are disabled to isolate the crosstalk effect.
check the Link this may help you.

Interchannel Crosstalk in Metro Networks

Thanks