Transcient responce of HOA

[Abhishek Shrama]

@damian ravil
Hello
Please inform me that how to check transient response of hybrid optical amplifier. I have tried it using OTDV by adding and dropping channel but couldnot find a way to check response.
I am attaching the link to research which I am following.

https://www.osapublishing.org/jot/abstract.cfm?uri=jot-81-10-590

[Damian Marek]

Are you using the dynamic model of the EDFA?

[Ravil]

Hi Abhishek,

Unfortunately, I don’t have an access to the article with the link that you’ve provided. Can you, please, share the scheme (with appropriate citations according to regulations) that you are working on? Did you try to obtain/measure a power/energy spectrum at the input and at the output of your amplifier? It is known that transient response of any amplifier is equal to the ratio of the output voltage (in case of electrical signal)/power to the input voltage/power…

[Abhishek Shrama]

Thank you damian for your reply,i do not understand which model i have to use whether it is dynamic or ARA in case of raman amplifier and EDFA. I have attached a file ,please look at this.
Ravil thank you too,I have one more problem,when i use this system in optisysyetm 7,noise figure at the dual port analyzer comes out to be 4db and less than that.But same systeem in optisystem 13 gives >50 db NF.Why it is so?

[Abhishek Shrama]

Fiber bragg garting i have used to reflect pump is take so much time for calculation,do i have to change max. no of iterations? When i once changed the max. no of itreations in case of EDFA,gain of the sysytem drop downs to lower values

[Ravil]

Hi Abhishek,

Unfortunately, I don’t have an access to OptiSystem right now to run your schemes. However, according to your question about the choice of amplifier (Raman & EDFA) I would recommend you to take a look at the following link (if you have not seen it yet): http://www.researchgate.net/profile/Juliano_De_Oliveira/publication/257362781_Hybrid_Distributed_RamanEDFA_Amplifier_with_Hybrid_Automatic_Gain_Control_for_Reconfigurable_WDM_Optical_Networks/links/0c960525063b2dc5dc000000.pdf

[Ravil]

It looks like the final choice of amplifier depends on your requirements: EDFA can achieve higher gain with the use of control loop, distributed Raman amplifier can have less noice with the proper gain control. I hope it will give you some ideas…

[Abhishek Shrama]

Hello Ravil and damian
Here i am attaching a file from optisystem 7 on the project i am working on.I have problem to plot graph .In optisystem RA DYNAMICS grapgh is different as compared to my graph.i just want to know how to set the values to get a graph as in example.see the attached graphs
First graph is from optisystem samples while 2nd one is of my system.

[Abhishek Shrama]

screen sh0ts

[Ashu verma]

Hello everyone
This topis is on the transcience response of amplifiers ,as i havnt much knolwlegde about the topic.But i have a common question about EDFa core radius and ions dopic radius.In some of the samples both in optisystem 7 and optisystem 13 values taken 1um ,1um sometimes and 2.2,2.2 in most of the cases in older version.Also i have seen value 3.2 also.Value of Numerical aperture is 0.24 and 0.31 some of the cases.what are the default values of these parameters in case of Edfa.if i use values 3.2 ym then is it practically feasible or what edfa with what values is available commercially.

[Alessandro Festa]

Hi Sam Sung, that depends on the type of fiber and amplifier. I suggest you open a new topic to discuss this item.

[Ashu verma]

Thank you Alessandro
I think in most of the cases ,different core radius used for gain flattening and access of more light into the doped fiber.But i would like to know some certain values and specification of EDFA.Yes i will start this topic for more understanding.Thank you fo your quick reply.

[Alessandro Festa]

EDFA companies (like mine 🙂 do not share details on the geometry of the fiber…you need to look at vendors of fiber themselves to know these details.

[Ashu verma]

Thank you Alessandro (Lolz),I was not aware of this thing.I was just looking for the some specification of EDFA,which are default and can be used as it is.Rest there are many values and i have gone through many papers where they can used different core radius numerical aperture for high gain and gain flatness.Optiwave itself used different parameters in their systems too.So now if i will going to study the EDFA through simulation then i can use any of the values since there are no typical values .isn’t it?
Case of RAMAN fiber amplifier is also smiler to this.Once again thank you for the rply

[Alessandro Festa]

Using any value is not a good idea since you could come up with results for efficiency/noise figure/flatness which are not realistic.
I think the best in this case is to use “Optical Amplifier” component.

[Abhishek Shrama]

@Damian,Please suggest me the way to correct the transience of attached system.I have attache two graphs ,but graphs are different .do i missing some factor or adjustments to take a right graph? Thanks in advance

[Damian Marek]

I can’t help you directly in OptiSystem 7 version files, because any file I attach will not be able to be opened by you and also because that version is quite old and I am not sure of all the changes that have been made since then!

That being said I can see that you are using the Average Power Model in your design, when you need to use the Raman Amplifier – Dynamic Model.

[Abhishek Shrama]

Hello Damian,I also have optisystem 13.I have tried the system with DYN model of Raman fiber amplifier too.But couldnt get exact results as shown in optiwave example.You make correction in the file using latest version ,i have access to the software.So please help

[Damian Marek]

I just copy and pasted the example file into yours and it works fine. All you need to do is change the bit rate so that the time window is large enough.

[Abhishek Shrama]

Thankyou Damian!!
You are always so very helpful and finally the one to solve issues

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