How to calculate mode overlap with I(x,y) rather than E(x,y)

In summary, the conversation discusses the use of a waveguide that is rectangular and multimode and is coupled to a standard telecom SMF28 fiber. The mode overlap is usually calculated by cross-correlation of the electric field, but in this case the only available information is the intensity distribution. The question then arises whether the calculation can be done by taking the square root of the intensity and assuming the imaginary part is equal to zero, or if the spatial symmetry of the modes can be used after mapping the intensity to a known mode.
  • #1
Fixar Frazze
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Hi

I have a waveguide that is rectangular and multimode that I but-couple to a standard telecom SMF28 fiber. I have imaged the output of the waveguide and the fiber with a 25X microscope objective onto the chip of an IR-camera. Usually the mode overlap is calculated by cross-correlation of the electric field (E(x,y)). Like

[tex]\eta=\frac{(\int E_1*conj(E_2))^2}{\int |E_1]^2*\int |E_2]^2}[/tex]

Now however I only have access to the intensity distribution I(x,y).

What do you think, can I justs take the square root of the intensity and perform the calculation and pretend the imaginary part is equal to zero?
 
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  • #2

FAQ: How to calculate mode overlap with I(x,y) rather than E(x,y)

1. How do I calculate mode overlap with I(x,y) instead of E(x,y)?

The mode overlap with I(x,y) is calculated using the formula:
MO = (I(x,y) / max(I(x,y))) * 100

2. What is the difference between using I(x,y) and E(x,y) to calculate mode overlap?

I(x,y) refers to the intensity of the light at a particular point (x,y) in an image, while E(x,y) refers to the electric field strength at that point. The mode overlap calculated using I(x,y) is a measure of the percentage of light in a particular mode, while the mode overlap calculated using E(x,y) is a measure of the electric field strength in a particular mode.

3. Can I use any type of light to calculate mode overlap with I(x,y)?

Yes, you can use any type of light as long as you have the intensity values for each point (x,y) in the image. This can include visible light, infrared light, or even radio waves.

4. How is mode overlap with I(x,y) useful in scientific research?

Mode overlap with I(x,y) is useful in studying the propagation of light through different materials and structures. It can also be used in the design and optimization of optical systems, such as lasers and fiber optics.

5. Can I calculate mode overlap with I(x,y) for a three-dimensional image?

Yes, you can calculate mode overlap with I(x,y) for a three-dimensional image by using the intensity values for each point (x,y,z) in the image. The formula for calculating mode overlap remains the same.

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