- This topic has 16 replies, 8 voices, and was last updated 8 years, 4 months ago by
Ranjeet Kumar.
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March 24, 2016 at 3:19 am #33659
aasif bashir dar
Participanthi all;
i got confused with the contineous wave laser component in the optisytem.
i was operating at the frequency of 193.1 THz…that by calculationlambda= velocity of light/frequency=3000000000/193.1THz=1553.6nm (approx)
but when changed laser frequency units from THz to nano meter(nm) …. to my surprise it shows 1552.524381149663nm
this is huge error in component or may be i am doing some thing wrong(plesae check all )
please admin reply this
with regards -
March 24, 2016 at 3:28 am #33660
aasif bashir dar
Participanthi all,
i am currenty using optisytem 14 (evaluation and licensed both)..i am attaching the screen shots for better understanding;
look in figure 1 the unit is THZand in fiqure 2 the unit is change to nm and it should be arround 1553.6 nm , but it far less than that…. then fiqures are colured for better visvalization….
with regards
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March 24, 2016 at 4:45 am #33666
FAYIQA NAQSHBANDI
SpectatorHELLO AASIF BASHIR..
I completely agree with you and it is an important point you have made here..actually i myself get confused sometimes when this happens it is not only with changing frequency.. i have seen this happening with power conversion also.. if you change power from dbm to milliwatts you get one value and when u convert same result back to dbm , there is variation by some decibels but it is manageable in that case..
bt in case of frequency to wavelength conversion it is a big issue since even .1 implies to huge values..Thanks & regards
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March 24, 2016 at 6:43 am #33673
aasif bashir dar
Participantyeah fayiqa naqshbandi,
it is actually ;
but optiwave people should respone to this problem here;;; so that our confusions are clear.
i also now it during power conversion processes… you are right about that fayiqa…with regards
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March 24, 2016 at 7:26 am #33680
FAYIQA NAQSHBANDI
SpectatorHI AASIF BASHIR..
You know it is not such a big problem in some some parameter conversions..however, in physical layout parameters like bit rate, frequency and wavelength this is a problem because as i mentioned in previous comment that in these cases even .1 decimal of difference means a lot while in other cases it is manageable.. still i hope the matter is cleared.
Thanks & regards
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March 24, 2016 at 7:44 am #33683
burhan num mina llah
ParticipantHi All
I was also facing the same problem. I won’t say problem coz it didn’t make much difference in regards to my project . I did attempt to change the frequency from THz to nm the value changed to some unexpected value but as u have mentioned in my case the value that i got for changing 193.1 THZ was not what i was expecting so i edited the values and took my results accordingly. I too would like to know hoq to overcome this.
Regards
Burhan
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March 24, 2016 at 8:02 am #33690
FAYIQA NAQSHBANDI
SpectatorHELLO BURHAN..
I think you have done the right thing by changing the values again to the desired values and i think this is the easiest and go to way to overcome this problem.. One should definitely check the values after converting them to other units and if the values are unexpected we should make sure we replace them with correct values…it has an impact on the results too..
Thanks & regards
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March 24, 2016 at 8:12 am #33694
Naazira Badar
ParticipantHi all..
Yeah that surely happens. But I don’t think that would bring any significant variation in the results.
May be they round off the values as per component compatibility.Regards.
Naazira . -
March 24, 2016 at 8:36 am #33711
aasif bashir dar
Participanthi all,
i at first thought that it is only my problem, but now looks that it is problem in software
i think this can not not overcome in any way @ burhan num minallah, because it is inherent in software.i is problem of software.. hope the optiwave people look on that
with regards
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March 24, 2016 at 10:40 am #33721
burhan num mina llah
ParticipantHi All
Aasif I don’t know how does it affect your project but in my case i had to just analyse the spectrum and i just forund that the spectrum just was smoother and hence a better result in regards to my project . Anyways best of luck with your case .
Regards
Burhan
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March 24, 2016 at 1:07 pm #33736
Sanjeev kumar
Participantthanks for the valuable suggestions friends
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March 24, 2016 at 1:14 pm #33737
SAHIL SINGH
ParticipantHi Sanjeev Kumar,
Indeed you are welcome… And thanks everybody for your valuable suggestions…
Regards
Sahil Singh
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March 24, 2016 at 2:35 pm #33749
Damian Marek
Participantaasif bashir dar,
The velocity of light is not equal to 3E8 m/s. It is actually 299792458 m/s:
https://en.wikipedia.org/wiki/Speed_of_light
Try the calculation again!
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March 24, 2016 at 3:14 pm #33751
SAHIL SINGH
ParticipantHi Aasif Bashir,
Indeed i agree with Damian about the numerical value as far as numerical value of velocity of light is concerned…. Also see the link as suggested in the previous post… It indeed will be very helpful to you..
Regards
Sahil Singh
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March 24, 2016 at 11:50 pm #33760
aasif bashir dar
Participanthi all
then calculations will be
lambda=299792458/193.1THz=1552.524381nm
…………….
thanks damain sirwith regards
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March 25, 2016 at 1:15 am #33769
SAHIL SINGH
ParticipantHi aasif bashir,
You are indeed right… Hope your problem is solved…
Regards
Sahil Singh
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March 25, 2016 at 2:02 am #33779
Ranjeet Kumar
ParticipantHi Aasif sir,
WDM wavelengths are positioned in a grid having exactly 100 GHz (about 0.8 nm) spacing in optical frequency, with a reference frequency fixed at 193.10 THz (1552.52 nm). The main grid is placed inside the optical fiber amplifier bandwidth, but can be extended to wider bandwidths. Today’s DWDM systems use 50 GHz or even 25 GHz channel spacing for up to 160 channel operation.
According to you “lambda= velocity of light/frequency=3000000000/193.1THz=1553.6nm (approx) but when changed laser frequency units from THz to nano meter(nm) …. to my surprise it shows 1552.524381149663nm”
The difference is nearly 0.8 nm.
It is due to channel spacing because by default channel spacing is 100 ghz(0.8 nm).
http://www.fiberoptic.com/adt_dwdm.htm
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