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optoelectronic oscillator

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(joined August 2015)
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I am presently working on the paper(attached pdf) but not getting any signal after the electroabsorption modulator. I think there is some parameter adjustment after the photodetector so please help me. i have also attached the .osd design file.

With regards

Attachments:
  1. 06502432.pdf

Responses (25):

  • #24490
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    Dhiman Kakati
    Participant

    I am presently working on the paper(attached pdf) but not getting any signal after the electroabsorption modulator. I think there is some parameter adjustment after the photodetector so please help me. i have also attached the .osd design file.

    With regards

    Attachments:
    1. 06502432.pdf
  • #24493
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    Dhiman Kakati
    Participant

    please find the attached .osd file so far as I have done.

    Attachments:
    1. Project11.osd
    +2
    • #24495
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      alistu
      Participant

      Hi Dhiman,

      I think the problem comes from the fact that the modulation port (which is electrical) of the electroabsorptive modulator does not have any value in the first run of the system. Therefore, it produces no output. So this port never gets any input value, as the its input is somehow dependent on its output.

      Regards

  • #24496
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    Dhiman Kakati
    Participant

    Dear alistu, I understand the problem you mentioned but how to overcome this. any suggestion..?

    • #24498
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      alistu
      Participant

      Since I am used to using Matlab for solving such problems, I might be able to suggest a scheme in which the first time the input is given by us and then it is obtained from the system itself as depicted by the paper. However, I don’t know how the process (or the simulation) is going to stop. Do you have any ideas about it?

  • #24499
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    Dhiman Kakati
    Participant

    Dear alistu, Thanks for your response, but I am Sorry to inform you that, I am also new to these disciplines so I also need some more time.

    • #24500
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      alistu
      Participant

      I am sorry I couldn’t simulate it with Matlab. I have attached what I tried though just to introduce the idea. The PRBS is used just to give initial initial values. I used three Matlab components. the first one just introduces a counter named “c” and also sends the initial signal to the modulators. Matlab component on the bottom left only takes the initial signal for the first time and the next times, it gets the signal from the fork (as it has to). Matlab component on the right only takes the values obtained from upper system (which works just for the start and works with initial values). I don’t know why it doesn’t work. And I don’t say the use of Matlab is by any means necessary in your case. It was just something that came in my mind..

      Attachments:
      1. Project11.doc
      +1
  • #24502
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    Dhiman Kakati
    Participant

    Dear alistu, I am grateful to you have tried in MATLAB, But unable to open the .doc file attached. If it is possible please provide me in a format that I can open in office 2013, or you can provide me in pdf format.

    Thanks.

    • #24504
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      alistu
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      You’re welcome Dhiman. I am sorry anyway that it does not give the desired answer. The file has osd format and you can open it with Optisystem. Just right-click on it and choose “open with option” and then choose Optisystem software. if not, open the Optisystem and then open the file by “open” option in the “file” menu.

  • #24510
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    Dhiman Kakati
    Participant

    Dear Alistu,
    Thanks, the attached file I can open in optisystem.

  • #24517
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    Dhiman Kakati
    Participant

    Dear Alistu, the design file u provided i tried to run in optisystem, but during simulation it stops responding, I think i need the MATLAB code.

    Thanks

    • #24518
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      alistu
      Participant

      Hi Dhiman,

      The Matlab codes are there at the MAtlab component properties. Please open any of the Matlab components and in the “run command” row, click on the small blue rectangle to see the code. By the way, there is no need to say Matlab should be installed on the computer before running your osd file.

      Regards

  • #24519
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    Dhiman Kakati
    Participant

    Thanks alistu I find the code and MATLAB 13 is installed in my system. but still not working. Though the .doc file is opening in optisystem but can you provide me with the .osd format.

  • #24525
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    alistu
    Participant

    Although the file opens and the simulation in my computer without any porblem, I saved it again to change the format to osd. Please let me know if this actually helps, as I remember some other people telling me they had some problem with my updated files in doc format in other topics.

    Attachments:
    1. Project111.osd
  • #24528
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    Dhiman Kakati
    Participant

    Dear alistu, Thanks a lot. it helps, I need to do some more mofification to have the required output.

    • #24529
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      alistu
      Participant

      You’re welcome. Please let me know if you could make it work. Thanks.

  • #24537
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    Dhiman Kakati
    Participant

    Yes definitely, When I will get the required output will inform You.

    With regards

  • #24780
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    Dhiman Kakati
    Participant

    Hi all, Unfortunately I am not able to get the output by changing the parameters also. so please help me..

    With regards

    • #24781
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      alistu
      Participant

      Hi Dhiman,

      Are you referring to the file that I uploaded here a while ago? Because as I told you then, I did not manage to get the proper results from that design. Please refer to my reply #24500 on this page.

      Regards

  • #25870
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    Dhiman Kakati
    Participant

    Hi Alistu,
    I tried so many times to get the result at the electrical domain by modifying the .osd design file you uploaded in reply no 24500, I followed one more book for this topic that is “broadband optical modulators, Science, Technology and applications” the circuit I uploaded before in the main question is aproximately same as that is in the book, if you have the book you can go through the pages 469-486,Sorry to say that I donot have the soft copy of the same. there they have not mentioned about any pulse requirement for the 1st cycle. I also think that there should not be any external pulse required for triggering the MZM (or electroabsoption modulator) for the 1st cycle as it is a oscillator (point of view).
    so anyone please help in this matter. Thanking you.

    Regards

    • #25872
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      alistu
      Participant

      Hi Dhiman,

      The reason for my suggestion was to find a way to make this work in OptiSystem, not based on the theory. Please refer to the comment I have addressed below, where I have described more or less the same issue:

      DPSK (BPSK) modulator using delay feedback

      Regards

  • #25902
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    Subhash Arya
    Participant

    Good discussion and efforts are putting to get the result. I encourage and thanks to Dhiman and Mr. Alistu for doing nice job of research work.
    I am also enriched by this discussion.
    Keep it up.

    With best wisehs,

    • #25903
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      alistu
      Participant

      I’m glad to hear it. Thank you very much for your compliment Dr Arya and thank you Dhiman for always bringing interesting topics to discussion.

  • #25904
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    Dhiman Kakati
    Participant

    Thank you sir and Alistu.

    Regards

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