optical add or drop multiplexer (OADM)

[Dr. Dhiman Kakati]

Hi everyone,
What is a optical add or drop multiplexer (OADM), How this works. I want to know the advantages and disadvantages for the same. do anyone one have any design regarding this.

Regards

[alistu]

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

[Tung Tran Van]

I want to simulate a DWDM network using ROADM. I’m using Optisystem v7, but I couldn’t find ROADM in a component library, only found ADM.
How can I design a ROADM?

[Dr. Dhiman Kakati]

Oh that will be very helpful if we can add/remove a channel at the remote station terminal using this in terms of flexibility. I will go through the examples and thank you so much.

Regards

[Atul Sharma]

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

[Dr. Dhiman Kakati]

Hello Atul Sharma,
I am not clear (understand) about the question and the line “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”, Where you want to change the parameters.
As far as I have understood your query, Yes you can add a optical modulated signal using the Add or Drop Multiplexer and extract also the modulated signal and then demodulate it.

WDM Add and Drop multiplexer. Equivalent to a combination subsystem based on the WDM Add and WDM Drop components.
You can refer to one sample at the WDM systems folder named COADM.

Regards,
Dhiman

[Atul Sharma]

Hello Dhiman. Good afternoon!

You have not understood my query. I meant that if we look into the add component only in the WDM library and see the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser. Now what about this added wavelength, can we change the modulation format of that signal only? or for that reason any other parameter.
I am not talking about add component as a modulator. I am talking of the ADDED WAVELENGTH/ ADDED SIGNAL. I hope you would have gotten my query now.
Regards
Atul Sharma

[Dr. Dhiman Kakati]

Hello Atul Sharman, Good Afternoo,
I was referring to modulation that you need to modulate as your wish of type (eg. QAM, DQPSK, BPSK etc.) but most importantly you need to modulate the optical signal before you apply to add drop multiplexer, and accordingly extract the signal of definite wavelength at the receiver side and apply respective demodulation and thats all, in this case you need to be very much careful while demultiplexing the signal at the WDM demux (i.e. central wavelength and bandwidth).

from your reply “the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser” this does not mean that you need to apply directly CW laser output to the OADM component. can do modulation as per your wish and then apply.

Regards,
Dhiman

[Atul Sharma]

Hello Dhiman. Greetings.

Well i completely agree with you when you are saying that we need to modulate as your wish of type like QAM, DQPSK, BPSK etc but most importantly we need to modulate the optical signal before you apply to add drop multiplexer, and accordingly extract the signal of definite wavelength at the receiver side. Undoubtedly.
I was able to change the modulation format of both the signals and got the desired results. Thank you anyway for your interest.

Regards
Atul Sharma

[Dr. Dhiman Kakati]

Hi Atul, I think your query is solved, Cheers.

Regards,
Dhiman

[love kumar]

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

[Dr. Dhiman Kakati]

Hi Love Kumar,
you are right that this technology is beneficial in Ring network topology. I am not finding your attached file, please reupload again. Thanking you.

Regards,
Dhiman

[love kumar]

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

[Dr. Dhiman Kakati]

Hello Love Kumar,
I think you answer is sufficient to understand for Atul Sharma issue, Please have a look that there is no attached file. This happens many a times that you attach the file in this forum and the file do not appear, I also put this issue to the optiwave forum management, but if you are still facing this issue, then we should look forward for answer from optiwave side. Thanking you.

Regards,
Dhiman

[Atul Sharma]

Hello Love Kumar. Greetings!

You have not understood my query. I meant that if we look into the add component only in the WDM library and see the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser. Now what about this added wavelength, can we change the modulation format of that signal only? or for that reason any other parameter.
I am not talking about add component as a modulator. I am talking of the ADDED WAVELENGTH/ ADDED SIGNAL. I hope you would have gotten my query now.
Regards
Atul Sharma

[Dr. Dhiman Kakati]

Hi Atul Sharma,
Please refer to my answer at reply no. #34283, you have misunderstood the line from component library “see the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser.” this does not mean that you have to add directly CW laser output, rather adding a unmodulated signal is of no use. if there is nothing information at the added optical wavelength this is of no use. just think it logically you can add a unmodulated signal using OADM but what context this will help you, because I think the working of OADM is very much clear to you. Thanking you..

Regards,
Dhiman

[Atul Sharma]

Hello dhiman. greetings.

checked that. Thank you for your help.

Regards
Atul sharma

[love kumar]

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

[Dr. Dhiman Kakati]

Hello love Kumar,
Thank you so much for providing with the pdfs. it helps a lot, and you can also have my mail id dhiman.kakati@gmail.com. I need some more time to go through the pdfs.

Regards,
Dhiman kakati

[love kumar]

find enclosed files

Attachments:

1. adm2.pdf

[Atul Sharma]

Thanks Love Kumar for sharing it.

[love kumar]

another one

Attachments:

1. adm1.pdf

[Ranjeet Kumar]

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.

[Dr. Dhiman Kakati]

Hello Ranjeet,
Thank you so much for providing more information about optical add drop multiplexer. Your effort is highly appreciated.

Regards,
Dhiman

[Ranjeet Kumar]

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

[Ranjeet Kumar]

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.

[Atul Sharma]

Hello ranjeet.
Thanks for replying but i don’t find your reply given by ranjeet very relevant. you are explaining something very different. Here i am asking a simple question about the added wavelength. These are the theoretical concepts you are posting here. I hope you try to understand my query and reply accordingly. Please try to be specific. Thanks for your anticipations anyway.
Regards
Atul Sharma

[Dr. Dhiman Kakati]

Hi Ranjeet Kumar,
thanks for adding some more information about the advantages of WDM multiplexer and WDM demultiplexer and disadvantages of Optical add drop multiplexer, both the component has best advantages on their respective application, and we can not interchange them for application purpose, and I agree with Atul Sharma, this is theoretical concept.

Regards,
Dhiman

[Ankita Sharma]

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

[Ranjeet Kumar]

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.

[Atul Sharma]

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

[SAHIL SINGH]

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

[Aabid Baba]

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

[Atul Sharma]

Hello Aabid baba. Good afternoon and GREETINGS.

Yes you are right we could do it and it is because of the forum i got lot of help and some guidance too. Anyway thank you very much for showing your interest. I appreciate your efforts.

Regards
Atul Sharma

[Aabid Baba]

You are welcome Atul.

[Dr. Dhiman Kakati]

Thank you Aabid Baba, for for your kind appreciation, I agree with you that uses of optical add drop multiplexer is very much application specific. we may apply advanced modulation schemes (which I am presently implementing) or a directly imprint a data to the light carrier and the add to the signal and drop also by selecting the wavelength.

Regards,
Dhiman

[Atul Sharma]

Hello Dhiman and Aabid. Greetings from my side.

Thank you both of you. I learned few things from this discussion and it was very helpful for me in every regard. Again thanks a lot.

With regards
Atul Sharma

[Ankita Sharma]

Hi all,

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

Regards
Ankita Sharma

[Author]

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