optical add or drop multiplexer (OADM)

Hi Dhiman,

Optical add-drop multiplexer is a component that can be used in WDM systems. In WDM systems, different channels have different wavelengths, are multiplexed in transmitter using WDM multiplxer and can all be demultiplexed at receiver. Sometimes it is desired to access or “drop” the information of one certain channel before the end receiver and/or add a new channel there. In these cases OADM can be used. You can find some examples in OptiSystem samples in “Add and Drop” folder.

Regards

Hi Dhiman.
I think you can help me.
I have a question you know i am testing a signal addition in WDM add component.. I have a confusion regarding the functionality of the add component. If i am transmitting a signal from the source end ( CW Laser) which is modulated ( using particular modulation scheme) and then supply this modulated signal to the add component ( whose reference wavelength is 1553nm or 193.1 THz) , Now my question is if the signal that is added by the add component is self modulated or i can change the different parameters of that signal.
I would like to hear from you.
Regards
Atul Sharma

hi Dhiman… yes you are guessing rigth .. we can add as well as drop channels at remote station .. this type of technique is preferred in metropolitan network specially in ring network topology .. attaching file for you reference

hi atul .. if i am right … you want to ask that adm will modulate the signal or we will c modulate the signal and thn given to ADM .. ADM is not a modulator .. we can use any modulation technique and than fed it to ADM..ADM is a multiplexer .. do treat it as modulator.. please follow thw files attached in my last post to Dhiman hope it will be helpful for you

hi dhiman .. uplaoding file again … if you dnt get it this time give me your email id i will forward to your inbox

find enclosed files

another one

Hi Dhiman,
Optical multiplexers are components specifically designed for wavelength division
multiplexing (WDM) systems. The demultiplexer undoes what the multiplexer has
done ; it separates a multiplicity of wavelengths in a fiber and directs them to many
fibers optical add-drop multiplexer (OADM) is a device used in wavelength-division multiplexing systems for multiplexing and routing different channels of light into or out of a single mode fiber (SMF).
A traditional OADM consists of three stages: an optical demultiplexer, an optical multiplexer, and between them a method of reconfiguring the paths between the demultiplexer, the multiplexer and a set of ports for adding and dropping signals. The demultiplexer separates wavelengths in an input fiber onto ports. The reconfiguration can be achieved by a fiber patch panel or by optical switches which direct the wavelengths to the multiplexer or to drop ports. The multiplexer multiplexes the wavelength channels that are to continue on from demultiplexer ports with those from the add ports, onto a single output fiber.

Hi,
The major advantages of optical add and multiplexers are:
low attenuation
large tun-ability
high stability
low cost
insensitivity to polarization flexibility
flexibility for choosing large number of channels without significant cross talk
it has both permanent or adjustable add and drop pattern

Hi,
But Optical add and drop multiplexers have the main disadvantages of high insertion loss and polarisation dependence. Comparatively, all-fiber devices are more attractive because of the low insertion losses, polarisation insensitivity and ease of coupling between output and input of the optical network by using simple splices and pigtails. But these devices are sensitive to environmental variations. There is another kind of devices based on free space optics (micro mirrors and gratings) also used to perform add-drop operations well. However, these devices have high insertion losses and cost much. So thin film filter devices have been used for multiplexing/demultiplexing applications.

Hi Ranjeet Kumar,

Thank you so much providing such valuable information about Optical add and drop multiplexers…This forum is indeed very helpful for all…

Thanks & Regards

You all are most welcome Dhiman sir, Atul sir and Ankita ma’m
I will try to improve myself and will try to share better explanations and more relevant concepts of the topic being discussed.
I agree to views , indeed optiwave forum is a very nice platform for us to get more benefits on optical communication and others related research to the optics.

Hello Ranjeet. Greetings!

Pleasure that you are ready to help. Very nice of you. Please do share any information you find useful regarding this. I will be really grateful to you. Actually i want to merge two signal with some sort of cross modulation. If i am transmitting a signal from CW laser with NRZ then is it possible for me to change the modulation scheme for the signal i am adding. I want to know if it is possible here. Will be looking to hear from you.
Regards
Atul Sharma

Hi Ranjeet Kumar,

thanks for providing such valuable information about the advantages of WDM multiplexer and WDM demultiplexer and disadvantages of Optical add drop multiplexer… Your efforts are highly appreciated..

Regards
Sahil Singh

Hi Dhiman Hello Atul Sharma,
As far as your query is concerned regarding adding a signal to an add component with different modulation scheme, yes you can do it easily. As per your system requirement you can easily use two different modulation schemes for both signals ( for one from the CW laser and one for the signal to be added in the add component). And yes you can easily change other parameters of the signals too. I hope you you would find it helpful. But it was an interesting question
Regards

Hi all,

Thanks all for providing such meaningful information particulary Aabid Sir and Damain Sir… Highly appreciate your efforts

Regards
Ankita Sharma