reflectivity of lens

[amani]

Hello all,
I need to specify the reflectivity of the lens by optisystem software.
I need to use a lens in my system with the following reflectivity values:
20.6% at 719 nm, 69.4% at 638 nm, 94% at 605 nm, 99.95% at 522nm

How I can get lens of these desired values ?
Thanks much for your help

[Damian Marek]

Hi Amani,

Is this an OptiFiber question? Are you using OptiFDTD?

Damian

[Heitor Galvao]

The optisystem makes this demand? I don’t think

[amani]

ok,
Thanks alot for your reply.

I use optisystem 13 trial version, can I use it to simulate this lenses?
What is the software program that enables me to do this task?

Thanks much for you

[Damian Marek]

OptiSystem simulates systems, so in this view you are setting the parameters of components and simulating the resulting system. If you want to design a component and extract these details then you are looking at OptiFDTD (which can handle reflections).

In OptiSystem we do not have an exact component for creating different reflections at different wavelegnths, although we do have a Thin Lens component for simulating a single wavelength signal. You could use the Matlab component to set these values.

Regards

[amani]

Thanks for your reply and interest,

Do you mean that I have two solutions for my problem: either using( FDTD ) or using ( optisystem with matlab component) .

If I truly understand , what is the easier and better solution according your experience in this field?

thanks for you

[Damian Marek]

The two solutions are different. In OptiFDTD you will design the lens and extract the reflectivity information. You will need to set the proper materials and geometry to attain your goals of reflectivity. In OptiSystem, you set the reflectivity and use the component in a larger system. To observe the wavelength dependent reflectivity you would need to use the Matlab component or you might be able to mimic the lens with a Fiber Bragg Grating.

Regards

[amani]

Thanks for your reply,

I prefer using the second solution, using optisystem and matlab component.

The problem now is that I need an example explains how to program the reflectivity of the lens on matlab.

I have a look on the pdf file (Matlab-optical -Example) which talks about attenuation .

How I can solve this problem?

Amani

[Damian Marek]

Depending on your exact application it might be possible to use components we have in OptiSystem to simulate the project. Do you only want to model loss of the signal at those wavelengths or is there something more, for instance modelling a reflected signal in time?

Let me know a few more details and if it is simple enough it should be no problem to simulate it directly in OptiSystem!

Thanks

[amani]

I need to simulate lens with the following specification:

I need to use a lens in my system with the following reflectivity values:
20.6% at 719 nm, 69.4% at 638 nm, 94% at 605 nm, 99.95% at 522nm

Thanks

[Damian Marek]

Yes, but are you interested only in the loss of power from the forward travelling wave or do you also want to model the back propagating reflection that is generated from this lens? Are you using the lens in a system?

Regards

[amani]

yes I used them in a system .

Only I need these specifications.
______________________________________________
I need to use a lens in my system with the following reflectivity values:
20.6% at 719 nm, 69.4% at 638 nm, 94% at 605 nm, 99.95% at 522nm
___________________________________________
by my system , the non reflected wave will be transmitted by fiber media.

Thanks

[Damian Marek]

In this case you could use a simple Inverted Rectangle Optical Filter and change the Depth (which is units of dB) to the corresponding reflectivity. You just need to convert reflectivity which is a fraction of powers to decibel units. Using four of these filters for each wavelength and a bandwidth of your choosing it should be straight forward to accomplish this directly in OptiSystem.

Regards

[amani]

Thanks much for your efforts.

I can use these filters serially, can not I ?

amani

[amani]

ok I connect them serially.

The problem that the program refused the -ve values of depth.

the dB values of (reflectivity < 1) are below zero.

How I can solve this problem>

thanks

[Damian Marek]

In the case of this filter a positive depth corresponds to a loss. It should be as simple as removing the minus sign!

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