2D power Splitter

[Poonam Jindal]

Hi

I am designing a 2D photonic crystal Y junction splitter. i wanted to know how to get the transmission characteristics post simulation analysis.

[Scott Newman]

Poonam,

You could place observation lines at your outputs and from there you can calculate the normalized power spectrum. Where you are given the power as a function of wavelength normalized to the input plane you have selected.

If you are referring to needing something similar to the S-Parameter functionality that is available in 3D then this would need to be done manually. Again using observation lines, multiple sources and exporting fields in order to do the calculations.

Scott

[Poonam Jindal]

Thanks sir

I have placed two observation lines at the two output ports of my designed Splitter and have obtained the graphs also. But I am unable to attain the information from these graphs. I have injected the Gaussian pulse at 1.55 micrometer but not getting any output at this wavelength. Can you please help me in interpreting these graphs. I mean what should i do to get the output efficiency in terms of percentage?
The same is attached for your reference.

[Scott Newman]

Poonam,

The attachment did not go through, were you attaching the design file? Could you please attempt to attach it again?

Scott

[Poonam Jindal]

Hi Sir

Please see the attchment

[Scott Newman]

Poonam,

Looks like there are issues with the attachment. Can you please send an email to support@optiwave.com with the file?

[Scott Newman]

I received your attachments through the support email. The plot for the observation line is reporting the amplitude of the selected field component (either Ey or Hx) along the observation line. The second plot is the power spectrum on the observation line. Assuming this observation line is one of your output ports and you have it normalized with your source this plot should be your transmission efficiency (Pout / Pin) versus wavelength.

I am a bit concerned with the magnitude of the plot as it appears to be values in the 10’s of thousands and you should not be seeing this level of magnification. I am assuming your source is a pulse, can you please provide the specifications for the source? Also Can you provide me with the file that you obtain by using the “Save as…” button on the Power Spectrum form?

[Poonam Jindal]

Thank you so much Sir. Your responses are of great help to me. The input source specifications and the power spectrum graph after clicking the save as tab are attached for your reference.

I also wanted to know that when my input source has a wavelength of 1.55 micrometer then how the wavelength (x axis of the graph) value is changed? Actually I am confused to find the output efficiency of my designed power splitter.

[Scott Newman]

Poonam,

There should be no confusion for the output efficiency. I have already explained that when you normalize the power spectrum you are looking at the power output efficiency. If you see 0.8 on your graph you have 80% efficiency.

Looking at the results from your observation line I believe there is something wrong with your design as it appears not a significant amount of power at the 1.55 mu range is reaching it. Are you able to just send the design file?

The “x axis” of the power spectrum is in fact the wavelength. The wavelength range that is calculated is based on the central wavelength of your source so yes this axis will change depending on what your source wavelength is set to.

Scott

[Poonam Jindal]

Dear Sir

Thank you so much for clearing my doubt on output efficinecy. My aim is to optimize the design of 2D Photonic Crystal based Power splitter in terms of output efficiency. I am injecting the input power at 1550 nm and have introduced certain defects in the crystal structure to get maximum efficiency. Refractive index of the substrate is 3.47 and air holes are injected in it with a refractive index of 1. the size of the splitter is 10×10 micrometer.the air hole radius is 0.2 and radius of defects is 0.1.
The problem is that I am not getting teh desired efficiency at 1550nm. I wanted to know where I am lagging.

[Poonam Jindal]

Dear Sir

I am resending the FDT file of my design.

Attachments:

1. 40-rods-modified1.fdt

[Scott Newman]

I believe the issue is partly the resolution you are using for the simulation as well as your general design. Please see the comments in the email I sent yesterday.

Scott

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