Home Forums SYSTEM optoelectronic oscillator

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    • #24490
      Dr. 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:
    • #24493
      Dr. Dhiman Kakati
      Participant

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

      Attachments:
      +2
      • #24495
        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
      Dr. Dhiman Kakati
      Participant

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

      • #24498
        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
      Dr. 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
        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
    • #24502
      Dr. 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
        alistu
        Participant

        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
      Dr. Dhiman Kakati
      Participant

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

    • #24517
      Dr. 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
        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
      Dr. 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
      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:
    • #24528
      Dr. Dhiman Kakati
      Participant

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

      • #24529
        alistu
        Participant

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

    • #24537
      Dr. Dhiman Kakati
      Participant

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

      With regards

    • #24780
      Dr. 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
        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
      Dr. 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
        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
      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
        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
      Dr. Dhiman Kakati
      Participant

      Thank you sir and Alistu.

      Regards

    • #42715
      Rohit Chhabra
      Participant

      Hey there. I have attached a schematics of the opto-electronic oscillator. I want to verify whether I am moving in the right direction or there is something wrong with the simulation. This oscillator loop is working fine as of now. Any comments are welcome. Thankyou.

      here is the link of the simulation https://drive.google.com/open?id=0B0pXVfDGnv7rTFRRZ20zZE10R1k

      Attachments:
    • #47827
      Surya Pratap
      Participant

      HI Dhiman Kakati,
      Did you get the solution for the above OEO problem? If so please let me know that would be a great help.

      Regards
      Surya

    • #54249
      nirmal pakhira
      Participant

      Hi, All
      i need some guidance how to trigger MZM modulator for an OEO. If anyone has an idea, please share…
      Thanks

    • #62466
      PRAKASHA PRAKASHA
      Participant

      Hello sir,

      I would like to know how far have you come with this research work ?

      I’m starting to work on the Optoelectronic Oscillator injection locked model. However, I saw your design in the document attached and it looks interesting to me.

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