Please someone help: Problem with Feed back loop

[Raja masud]

Hello I am currently doing my thesis for my BSc degree, I am working with optical memory, and I have found an U.S patent (you can find this patent in this link: https://www.google.com.ar/patents/US5533154), which is about an optical memory, I have simulated this in optisystem-7, but I did not get any output. Why it is happening? Can any expert brothers or sister help me with details? I am waiting for reply. Anyway, I am new to optisystem-7. I have attached a pdf file also, please brother read this file first.

regards
Raja

[Ashu verma]

Hello Raja
First of all, All optical devices is very interesting area now a days.I am also working on all optical gates and latches.Optical storage devices are really in demand now due to better storage quality an speed of storing and small size.I have seen your file that you have attached.I would like to suggest you some forum archives on this topic.There are some discussions already done on feedbacks in the all optical system.Please visit the links given below

JK Flip Flop

All optical D-FF using BD filter interleaving

Feedback in all optical circuits

Feedback Signal

Regards

[Ashu verma]

According to your doubts,I have made some points to help you
1. If you want to fetch a single pulse then set the value of sequence length 1 or 2 in global parameter window
2.Please attach the simulation file in order to understand your system and what type of problem is in your system.Generally problem with feedback is,that you are getting no results a vizulizers.
3.You can use OTDV for this purpose(I am not sure because pulses should be of different time slot).
4.With default otdv you can check the transmitted pulse if transmitted pulses are of small sequence length.In other case you have to check this from OTDV by manually enter the no. of bits you wish to see.
5.In case of feedback you can use optical couplers.but do not let any port free.attach null signal and ground at empty ports.Try to use optical fiber in case of feedback path(It works for me many times,but i am not sure that it will for you too).

Please attach your system file so that other optiwave forum members able to help you.

Regards

[Raja masud]

thank you Sam Sung for your quick reply, i have look those links you provide but i did not find the all answer of the question i asked. i have generate a single pulse according to your suggestion. but still my system is not working. here my osd file

[Damian Marek]

Attached is a screenshot of how you would approach this problem. I’m not sure if all of these components are available in OptiSystem 7 but if they are it is pretty straightforward to build.

Attached is also my project file, but since you only have OptiSystem 7 you will not be able to open it. If you try an evaluation of OptiSystem 13.0 then you will.

Cheers

[Damian Marek]

I forgot to explain the Initializer in my previous post. It is really the key component along with the Optical Ring Controller.

The Initializer allows you to start a ring simulation with an initial field, in subsequent iterations it will propagate the optical signal around the loop indefinitely. That is unless of course you use a Optical Ring Controller, which will tell the simulator to stop the calculation after a number of loops. There is also a convergence tool you can use that will stop the simulation when the signal reaches steady state, however in this case the signal is constantly changing, so I chose to control the number of loops explicitly.

Regards

[Raja masud]

thank you Marek for your answer,
but i am still confused, so can i ask some question to you?

[Raja masud]

hello, Marek,
i have shown your design to my supervisor, but he told me not to change the design in simulation. so is there any other way to simulate this memory without distorting the design? if any then it will help my project.
regards
raja

[alistu]

Hello Raja, May I ask you to mention your supervisor’s opinion on the suggested design more specifically? The system suggested by Damian works fine. Can you tell about what you are looking for more specifically and some features or characteristics that you might be looking for? So that we can help you better. Thanks.

[Raja masud]

hi alistu,
thanks for your reply

i have upload a new topic https://optiwave.com/forums/topic/plz-help-me-to-solve-3-questions/ where you can find 3 specific questions we(my group) are looking for.

Thanks again

[Taiwo Ambali Abiola]

I think the best solution is what you have gotten from Marek.

[Mohamed Elgaud]

hello everyone, is there any possibility in Optisystem to work with different bit rates between the main layout (the global parameters) and the bit rate in the user defined pulse generator? I need to work with 10ns pulse (single Pulse) width while the main layout bitrate equal to KHz values (almost 102Khz) Thank you

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