change in phase of the sinusoidal signal versus variation in the fiber length

[Aadil Raza]

I would like to ask one thing. I want to Transmit a sinusoidal wave over fiber by using a CW laser, a modulator, dispersion compensating fiber, a photodetector and an electrical filter. I want to observe the change in phase of the sinusoidal signal versus variation in the length of the fiber. is there any equipment in VPI that can measure phase of a sinusoidal signal. what parameters of a commonly used DCF are?

Please guide

[Damian Marek]

I’m not sure about VPI, but this is definitely something you could do in OptiSystem. The best way to go about it would depend on exactly what you want to investigate. Do you want to calculate the time delay of the entire signal after propagating through the fiber or are you interested in some phase delay between different modes? The first result could be found simply from the Clock Recovery component and the second could be retrieved from the Differential Mode Delay component.

Cheers

[Ravil]

I’ll probably try to use modulation with binary sequence of short duration (in comparison with you CW). What frq/wavel. are you using by the way?

[Aadil Raza]

Thanks for reply. I am using 1550nm wavelength and 2.5Gbps bit rate.

[Aadil Raza]

As I am new to optisystem I don’t know to how to connect Clock Recovery component and the Differential Mode Delay component. I tried to connect Clock Recovery component at the end to o observe delay but its reference input is not connecting with input electrical signal. Also tell how to observe delay, I mean what about output port of Clock Recovery?

[Damian Marek]

The Clock Recovery component works by comparing a reference signal to the output signal (both electrical). It will automatically adjust the output signal by shifting it. It also stores the time delay value in the result section (Check the Project Browser or right-click the component and navigate to Component Results).

If you are using OptiSystem 13 you should be able to open the attached project file, where I implemented the time delay component.

I would not worry about the DMD component if you are not working with multimodes.

Regards

Attachments:

1. delayExplanation.osd

[Aadil Raza]

Thanks. I have optisystem 7. Don’t have access to optisystem 13. I would be grateful if you share the schematic snapshot of that
Project file.

[Ravil]

I’d like to see it as well, pls. Damian, are we able to extract clock signal optically from line signal by using OptiSystem?

[Aadil Raza]

This worked now and after calculating the time delay from clock recovery component,one can easily found change in phase…thanks for guideline. Keep blessed…

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