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Full Name | Thomas Freir |
Organization | Dublin Institute of Technology |
Job Title | Lecturer |
Country |
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I figured out the second question, it was the fibre dispersion.
Can anyone from the optisystem team answer the first part.
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Graph of wavelength versus BER
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Can someone from the optisystem team have a look at this please?
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How did you view the output as log of BER and frequency? Used the report function
But I checked the component results of BER analyzer and I saw the min Log BER as -86.041. I am not sure whether it is right or not. Just giving an idea. (After you run the simulation did you check the BER for each sweep, not just the last one)?
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Graph attached
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Simulation is attached
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Thanks for that, I presume you mean the power combiner on page 1293
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Sorry
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Simulation
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Result graph
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Under ideal circumstances Laser 1470 would arrive at power meter 1 with a power of -10dBm. Laser 1490 would arrive at power meter 2 with a power of -10dBm.
The picture “Result” shows the power measured at power meter 2. You will see that the lowest power on this graph is -10dBm. This is the expected power from the 1490 laser. In addition to this there is a gaussian shaped bulge. This is an unwanted leakage of power from the 1470nm laser as its wavelength is swept over a range. I would expect this result and have confirmed it elsewhere.
The unexpected result is the spike of optical power to the right of the gaussian shaped bulge.
The reason I am building this model is that CWDM lasers are expected to drift in wavelength domain. I know the drift in this case is excessive but I am trying to validate the model.
Thanks for your time.
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The WDM mux and demux are band pass filters with a Gaussian response. As the CW laser has its wavelength changed some of the CW laser will leak through. The MUX and demux are not ideal.
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Don’t mind the range I have swept over. This is just so I can see how the filters perform. In practice the lasers will only be drifting by a few nanometers.
Remember in CWDM systems the lasers are allowed drift from their central wavelength by plus of minus 6.5nm. I want to explore how this wavelength drift effects adjacent channels.
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I had to attach the pictures separately.
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Thank you for the reply Damian,
I am trying to model a CWDM system using typical values for transmitters/lasers from manufactures data sheet. Linewidth is typically specified in nanometers usually 20dB from the peak. I have yet to identify a data sheet for CWDM lasers that specifies the phase noise. How would you suggest I proceed?