Search Results for 'wdm'

[aasif bashir darParticipant]

hi atul sharma,
combiner…..combines two optical input signals.
Optical circulator. You can control insertion loss, return loss, and isolation.
WDM ADD.Adds a WDM channel and a WDM signal.

for the technical background of each of the coomponent , i suggest you to go through the component help in the optisytem….

with regards

[aasif bashir darParticipant]

the drop module is simlar to that of the add mux in technical back ground however..it Drops a WDM channel from a WDM signal.
add drop mux…Equivalent to a subsystem based on the WDM Add and WDM Drop components.
In the drop section, the input signal is divided in two signals. Each signal is filtered by an optical filter. An inverse filter filters the first signal.
In the add section, the input signals are filtered by an optical filter and are combined in one signal. An inverse filter filters the first signal.
The optical filters can be a Rectangle, Gaussian, or Bessel optical filter.

with regards

[aasif bashir darParticipant]

hi aabid baba,
add module,……………..Adds a WDM channel and a WDM signal
technical back ground
The input signals are filtered by an optical filter and are combined in one signal. The first signal is filtered by an inverse filter. The optical filters can be a Rectangle, Gaussian, or Bessel optical filter.
Defining crosstalk
The level of crosstalk for both MUX and DEMUX components, is defined by bandwidth, ripple, and depth of the filter. These 3 factors will determine how much power, from neighboring channels, will act as crosstalk terms when calculating the performance of a specific channel. The most important parameter is depth, as it will play the most significant role in determining the power levels of the neighboring channels.

[SAHIL SINGHParticipant]

Hi Ranjeet Kumar,

thanks for providing such valuable information about the advantages of WDM multiplexer and WDM demultiplexer and disadvantages of Optical add drop multiplexer… Your efforts are highly appreciated..

Regards
Sahil Singh

[Ranjeet KumarParticipant]

Hi,
For more information on unequal channel spacing wdm system, I would suggest you to get some focus on research papers , i share some links of that:
http://link.springer.com/chapter/10.1007%2F978-1-4020-8741-7_1#page-1
https://www.researchgate.net/publication/261320396_Duobinary_modulation_format_and_unequal_channel_spacing_integration_to_suppress_four-wave_mixing_crosstalk_in_WDM_systems
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5876926&abstractAccess=no&userType=inst
http://www.ijarcsse.com/docs/papers/Volume_3/12_December2013/V3I12-0112.pdf

[Ranjeet KumarParticipant]

Hi,
Four Wave Mixing crosstalk suppression can be achieved by using unequally spaced channel allocation methods such as integer linear programming (ILP), extended quadratic congruence (EQC) algorithm, search algorithm (SA), disjoint difference sets (DDS), and optimal Golomb ruler (OGR) sequences. The main contribution of this paper is to presents a brief survey on the ILP, EQC, SA and DDS and detailed survey on OGR sequences proposed in literature for FWM crosstalk suppression in WDM systems.
The use of proper unequal channel spacing keeps FWM signals from coherently interfering with the desired signals.
An optimumUSCA (O–USCA) technique ensures that no FWM signals will ever be generated at any of the channel frequencies if the frequency separation of any two channels is different from any other pair of channels in a minimum operating bandwidth.

[jyoti rainaSpectator]

Thanx Dhiman sir for ur kind reply..i think u are asking about the frequency spacing??
i am giving 100 Ghz spacing between the four transmitted frequencies…i am also using wdm mux with 15 Ghz bandwidth..bcoz somewhere on the forum i read it gives u better results so i increazed it to 15 which i think is nt dat much…i hope i am not doing wrong…dhiman sir i hv one query abt plotting graphs for all 4 receivers on the same graph for ber abd q factr…bt m nt able to do it at a time fr all..cn u plz tel me if i can do it..i vil b very much thankful…thanx in advnce

[Dr. Dhiman KakatiParticipant]

I agree with Sanjeev Kumar that in my case also a single transmitter and receiver (i.e. without WDM) I am able to get a maximum Bit rate of 10 Gbps. Urvi You also should try to reduce the bit rate at each transmitter to a maximum of 10 Gbps.

Regards,
Dhiman

[Dr. Dhiman KakatiParticipant]

Hi Kevin Xiang,
I am not getting your point, Will you please elaborate. Why you have suggested polarization mode splitter, How it is going to help (except for twice the bit rate) we have not implemented polarization splitting technique here.

” we produce 405nm,532nm,635nm,650nm~1650nm splitter,WDM, such as 532/635nm PMWDM etc, which are used in OCT, QPSK ,EDFA, etc.” are you referring to practical implementation or practical design not a simulation platform..? looking forward for your kind response. Thanking you.

Regards,
Dhiman

[Dr. Dhiman KakatiParticipant]

You are most welcome Jyoti Raina, The spectrum image you have attached here is quite Good as there is no overlapping now. I think you should get better result now but one thing i need to mention that how much frequency separation you are giving to get this Spectrum at the WDM mux output because if you give more than a limit you will not be able to transmit longer distance. Thanks for uploading.

Regards,
Dhiman

[Dr. Dhiman KakatiParticipant]

Hi Ranjeet Kumar,
thanks for adding some more information about the advantages of WDM multiplexer and WDM demultiplexer and disadvantages of Optical add drop multiplexer, both the component has best advantages on their respective application, and we can not interchange them for application purpose, and I agree with Atul Sharma, this is theoretical concept.

Regards,
Dhiman

[Dr. Dhiman KakatiParticipant]

Hello Atul Sharman, Good Afternoo,
I was referring to modulation that you need to modulate as your wish of type (eg. QAM, DQPSK, BPSK etc.) but most importantly you need to modulate the optical signal before you apply to add drop multiplexer, and accordingly extract the signal of definite wavelength at the receiver side and apply respective demodulation and thats all, in this case you need to be very much careful while demultiplexing the signal at the WDM demux (i.e. central wavelength and bandwidth).

from your reply “the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser” this does not mean that you need to apply directly CW laser output to the OADM component. can do modulation as per your wish and then apply.

Regards,
Dhiman

[Atul SharmaParticipant]

Hello Love Kumar. Greetings!

You have not understood my query. I meant that if we look into the add component only in the WDM library and see the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser. Now what about this added wavelength, can we change the modulation format of that signal only? or for that reason any other parameter.
I am not talking about add component as a modulator. I am talking of the ADDED WAVELENGTH/ ADDED SIGNAL. I hope you would have gotten my query now.
Regards
Atul Sharma

[Atul SharmaParticipant]

Hello Naazira Badar.Greetings!
Hello Dhiman. Good Morning!

For reference you can check the optisystem samples and find it there in WDM folder. I actually want to check the functionality of the add component. We know it simply adds a wavelength into the transmitted signal from the CW Laser. Now what about this added wavelength, can we change the modulation format of that signal only? or for that reason any other parameter.
I hope you would have gotten my query now.
Regards
Atul Sharma

[Atul SharmaParticipant]

Hello Dhiman. Good afternoon!

You have not understood my query. I meant that if we look into the add component only in the WDM library and see the functionality of the add component it simply adds a wavelength into the transmitted signal from the CW Laser. Now what about this added wavelength, can we change the modulation format of that signal only? or for that reason any other parameter.
I am not talking about add component as a modulator. I am talking of the ADDED WAVELENGTH/ ADDED SIGNAL. I hope you would have gotten my query now.
Regards
Atul Sharma