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TWDM

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(joined June 2015)
Participant

Hi everyone,
On April 2012,after the meeting of the Full Service Access Network (FSAN) group,
time and wavelength division multiplexed passive optical network (TWDM-PON) technology
was chosen as the primary solution for next-generation passive optical network stage-2 (NG-PON2) architecture,
the evolving specifications are wavelength plans, loss budgets, and key technologies that enable tunable ONUs.

So, i want to work on time and wavelength division multiplexed PON.
I have tried to design TWDM-PON in optisystem , but didn’t get results.
I request you all to please , if possible to Upload the osd file of TWDM-PON.
So, that i could enhance the system.
You could even share some important links related to it.

Seeking your response.

Responses (26):

    • #37214
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi everyone,
      On April 2012,after the meeting of the Full Service Access Network (FSAN) group,
      time and wavelength division multiplexed passive optical network (TWDM-PON) technology
      was chosen as the primary solution for next-generation passive optical network stage-2 (NG-PON2) architecture,
      the evolving specifications are wavelength plans, loss budgets, and key technologies that enable tunable ONUs.

      So, i want to work on time and wavelength division multiplexed PON.
      I have tried to design TWDM-PON in optisystem , but didn’t get results.
      I request you all to please , if possible to Upload the osd file of TWDM-PON.
      So, that i could enhance the system.
      You could even share some important links related to it.

      Seeking your response.

    • #37215
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi,
      I know some of basic parameters, technologies and requirements related to it like:
      Tunable transmitters comprises of
      Distributed feedback (DFB) laser with temperature control (TC),
      External cavity laser (ECL) with mechanical control without cooling,
      Tunable receivers with following :Liquid-crystal tunable filter,
      Thermally-tuned Fabry-Perot (FP) filter
      The prototype of TWDM employs the C-band wavelength plan to achieve coexistence
      with the previous generations of PON, while the four downstream wavelengths are spaced 200GHz apart.

      So, please share some advanced and necessary elements related to it.
      Thanks and Regards,
      Rajguru

      +2
      • #37751

        Hi RAJGURU..

        Thank you for sharing this piece..It might be very useful.

        Regards
        FAYIQA

        +3
    • #37223
      Profile Photo
      nagesh kuknoor
      Participant

      Hi ranjeet,
      Thank you for sharing such information. Well i have heard of tunable lasers for improving system performance. And also about the externally modulated lasers for the same thing. What actually you want to implement?

      Regards

      +3
    • #37323
      Profile Photo
      Ankita Sharma
      Participant

      Hi Rajguru,

      Thanks for sharing information… I agree here with Nagesh, about tunable lasers for improving system performance..

      Regards

      +2
    • #37353
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi Nagesh,
      As i have discussed that i want to basic TWDM system like 4 users.
      I have asked for osd file of TWDM system.
      If possible, at least share instructions to design TWDM system properly, this may be in the form of image or pdf or links.

      If you know how to implement tunable lasers for improving system performance and externally modulated lasers in optisystem.
      Also share this.
      Regards,
      Rajguru.

      +1
    • #37355
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi ankita,
      Please suggest some links or instructions for implememtation TWDM system.

      Regards,
      Rajguru

    • #37731
      Profile Photo
      Rahul Tiwari
      Participant

      Hi Rajguru,

      I also agree with Nagesh about The fact that tunable lasers improve system performance..

      Regards
      Rahul Tiwari

      +2
    • #37736
      Profile Photo
      Kanwarjeet Singh
      Participant

      Hello Rajguru,
      I want to know if thermally tuned fabry parot lasers are available in optisystem. I would appreciate your response. Thanking you.

      Regards
      Kanwarjeet

      • #37750

        HELLO KANWARJEET..

        As far as i know there are no such filters in Optisystem . hope it helps.

        Regards
        Fayiqa

        +2
        • #37752
          Profile Photo
          Kanwarjeet Singh
          Participant

          Hi Dear,
          Thank you for it. I thought Mr. Rajguru has shared it with that purpose only. Anyway Thank you.

          Regards

        • #37753

          You are welcome anytime.

          +1
        • #37768
          Profile Photo
          Kanwarjeet Singh
          Participant

          Thanks Dear for the gratitude.

          Regards
          Kanwarjeet

        • #37769

          Cheers..

    • #37785
      Profile Photo
      Rahul Tiwari
      Participant

      Hi all,

      Which filters are not there ?

      Regards
      Rahul Tiwari

    • #38257
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi kanwarjeet,
      I think we don’t have thermally tuned fabry parot lasers in optisystem tiil date.
      Hope it would be added in component library soon.

      Thanks

    • #38258
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi Ankita,
      We have lots of benefits of tunable laser. They are as:
      As tunable lasers are classified into three structural types: an external cavity laser,
      a distributed feedback (DFB) laser array, and a distributed Bragg reflector (DBR) laser.
      All of these laser structures provide a tuning range of more than 35 nm, which is required for DWDM systems.
      Another important aspect of the tunable lasers
      performance, when switching between wavelengths, is
      the wavelength stability of the device. As the laser tunes
      into its desired wavelength, there is a settling drift before
      the channel finally stabilizes. This drift can have a large
      impact on the performance of a dense wavelength
      division multiplexed system (causing adjacent channel
      interference) and therefore must be fully characterized, in
      terms of both the magnitude of the drift and the time it
      takes to settle to the destination wavelength.
      The external cavity laser which can an easily provide a wide tuning range because optimum optical filters can be selected.
      This laser is a strong light source for digital coherent systems.
      Its drawbacks are that complex tuning control is needed to suppress mode hopping and that it has many optical parts.

      Thanks

      • #38269

        HELLO RAJGUR..

        That is exactly what i had mentioned earlier..We have no of benefits by using tunable lasers at the receiver end..I hope it helps you.

        Regards

        +1
    • #38259
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi,
      Now i am adding the benefits of 2nd type of tunable laser i.e. distributed feedback (DFB) laser array.
      The DFB laser array is based on the DFB laser, which has been widely used in commercial optical networks for a long time.
      The tuning range is expanded by integrating DFB lasers of different wavelengths.
      An excellent feature of this laser is its mode stability and
      reliability owing to its mode-hop-free tuning characteristics.
      Moreover, it is suited to mass production because it is a monolithic chip.
      Its drawback is its slow wavelength tuning, which is achieved through temperature control.
      DFB array lasers are widely used in current 10-Gbit/s systems.
      The linewidth of the conventional DFB laser is several megahertz.
      However, a narrower linewidth can be obtained by optimizing the cavity structure.

      Thanks

    • #38260
      Profile Photo
      Rajguru M. Mohan
      Participant

      Hi,
      And finally we have distributed Bragg reflector (DBR) laser.
      A DBR laser is also a monolithic chip. The wavelength can be tuned by
      controlling the refractive index of the semiconductor-based DBR.
      Generally, the refractive index is changed by a carrier plasma effect induced by current injection.
      Therefore, the tuning time is a short as a few nanoseconds.
      Its drawback is that the linewidth is increased when the tuning current is injected.
      However, it has been reported that a DBR-type laser with heaters for
      temperature-based wavelength tuning has a narrow linewidth even during wavelength tuning.

      The all benefits and some drawbacks of tunable lasers being discussed.

      Thanks

    • #38270

      HI RAJGURU..

      Thank you for the valuable information..I appreciate that.

      Regards

    • #38371
      Profile Photo
      Rajguru M. Mohan
      Participant

      You are most welcome FAYIQA NAQSHBANDI.

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