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Power recorded across the observation vertical lines, comes negative.

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(joined February 2021)
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Dear Sir/Madam

We are launching a pulse in the designed resonator and trying to get Normalized transmission v/s wavelength for designed structure. Pulse is having central wavelength of 1.5 um and 2D transverse half width as 1.5 um. Issues and queries which we have are as follows

(1) After completion of simulation, when we go to analyzer file, observational vertical line L3 is showing power with negative values. We are getting negative value of power across L3 when calculating power corresponding to each wavelength in observational area analysis under Analyzer window. We have observed that whenever observation line record/sense the signal propagating either in negative X or Z direction, it gives negative value of power. Should we only note the magnitude of power only ignoring the negative sign in these cases?

(2) In order to get power at particular wavelength for particular port, We note the value of power corresponding to observation line placed at that port in observational area analysis under Analyzer window. Are we correctly doing this? is this the way to get the power at particular port?

(3) How do we get the raw data of power spectrum corresponding to each observational line placed against each port in the design?

For reference we also attached design file.

Thanking You

Regards

Man Mohan Gupta

Responses (3):

    • #69880
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      Man Mohan Gupta
      Participant

      Dear Sir/Madam

      We are launching a pulse in the designed resonator and trying to get Normalized transmission v/s wavelength for designed structure. Pulse is having central wavelength of 1.5 um and 2D transverse half width as 1.5 um. Issues and queries which we have are as follows

      (1) After completion of simulation, when we go to analyzer file, observational vertical line L3 is showing power with negative values. We are getting negative value of power across L3 when calculating power corresponding to each wavelength in observational area analysis under Analyzer window. We have observed that whenever observation line record/sense the signal propagating either in negative X or Z direction, it gives negative value of power. Should we only note the magnitude of power only ignoring the negative sign in these cases?

      (2) In order to get power at particular wavelength for particular port, We note the value of power corresponding to observation line placed at that port in observational area analysis under Analyzer window. Are we correctly doing this? is this the way to get the power at particular port?

      (3) How do we get the raw data of power spectrum corresponding to each observational line placed against each port in the design?

      For reference we also attached design file.

      Thanking You

      Regards

      Man Mohan Gupta

    • #69882
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      Scott Newman
      Moderator
      1. The observation lines and areas take note of the direction of the power and therefore the sign indicates this direction. In the case of your observers positive power corresponds to power moving in the +ve Z direction and similarly negative power corresponds to power moving in the -ve Z direction.
      2. Your procedure is effectively correct.
      3. This will depend on what you mean by “raw data” are you looking for the fields? Within the detector analysis there is an export data button which will allow you to export the spectrum. Similarly if you are viewing field data you can export that.

      Scott

    • #69883
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      Man Mohan Gupta
      Participant

      Dear Scott

      Thanks for for valuable comments and suggestions.

      1. Sir, should we then ignore negative sign and only pick the magnitude of power recorded by observational line if line is recording the signal propagating in negative direction?

      Thanking You

      Regards

      Man Mohan Gupta

    • #69886
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      Scott Newman
      Moderator

      I would not say ignore it specifically. I would see it make note that it means the power is going in the negative direction and then note the absolute value of the power.

      Scott

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