Plasmonic sensor

[Hardik Mathuriya]

Hello,
I am trying to simulate a paper based on SPR sensor using MIM geometry. As I am new to OptiFDTD I am finding difficulty in designing its stucture. Can anyone please help me in the implementation of this paper.

[Scott Newman]

Hardik,

You are going to have to be more specific in regards to what you are having difficulty with. Based on the geometry of the paper you are citing you will be running a 3D simulation. The membrane and slits will need to be created using linear waveguides. Do keep in mind when dealing with waveguides you must first create a profile describing the cross section of the waveguide and then when you create the waveguide you are creating the path.

I would suggest you check out some of our introductory webinars as I believe they would be very beneficial for someone first experiencing the product, https://optiwave.com/category/resources/webinars/. Look for the link to view all the webinars and find OptiFDTD Introduction.

Scott

[Hardik Mathuriya]

Thank you Mr.Newman

I have following queries-
1) I have attached my design file, will you please tell me that how should I create the structure described in the paper as I am not able to replicate it. Should I create different channel profiles instead of adding different layers in a single profile and please also tell at what position should I add the stubs.

2)It is mentioned that input field is injected in positive x direction but I can not calculate modes in the mode solver because it does not show the position of the waveguide.

Regards

[Scott Newman]

Hardik,

I strongly recommend that you watch the introductory webinars and look through some of the examples that come with your installation. There are a number of issues and unfortunately I do not have the resources to do one on one training.

Answers to your questions:
1. You do not need a profile for each layer the one profile is sufficient, it should be the cross section of your profile. I am not certain what you mean by stubs but your design has one waveguide and the design in the paper is a cross pattern. Use the linear waveguides and place them where you see the features in the paper.

2. In the design you attached you have a z-directed input plane and not an x. Additionally you have it set to Gaussian not modal for the transverse profile. Do keep in mind that the input plane must cross the waveguide in order to calculate a mode.

Something for you to be aware of:
1. Your resolution (set in the 3D simulations item within the project browser) is far too high. The auto setting is based on your source wavelength to ensure it is stable. However, you have feature sizes (in your case layer thicknesses) as low as 0.01. Your resolution must be such that the structure is properly discretized.

Scott

[Hardik Mathuriya]

Thank you so much Sir

[Hardik Mathuriya]

Hello Scott Sir,

After watching the introductory videos and simulating some basic examples I have designed the sensor and looking at the refractive index profile, it seems to be in accordance with the proposed geometry of the paper. light is able to couple into the structure but still I am not getting the desired results. Will you please take some time and look into my design and help me proceed further . I am also attaching the reference paper.
Thank you

[Scott Newman]

You have not attached an updated design file. I already provided feedback on the one you attached earlier. Do keep in mind that without having a maintenance license, I am assuming you are using the 32-bit, my support is necessarily limited to helping with issues in the product. We are not able to provide design assistance.

Please provide specifics on the issue you have, i.e. how is your results not the desired results, and I can see what I can do.

Scott

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