Aperiodic Diffraction Grating

[desertshaman]

TL;DR

I wonder whether this geometry has been tried to make a monochromatic source?

Hi People :)


The drawing shows a broadband light source illuminating a diffraction grating whose lines are spaced differently along the grating.

The blazed lines of the grating are spaced in such a way that the path length from every line to the slit is one wavelength shorter than the line before it and one wavelength longer than the line after it.

I wonder whether gratings of this kind have been tried, please?

Mark

 

[Ibix]

I don't know about that particular geometry, but non-repeating diffraction gratings are fairly common. Holograms are one example.

You can compute what the far field diffraction pattern of any slit structure would be - it's just the Fourier transform of the aperture function. I suspect it would have to be done numerically, so with a slit pattern that's getting narrower and narrower you might find that numerical precision is an issue that needs some careful handling. If you're planning to compare it to experiment you'd also need to be careful about what counts as "far field" for the maximum line separation, or do the (harder) near field calculations.

 

[desertshaman]

:) Thank you for that, @Ibix
I now see that what I'm thinking of making, by blazing razor lines onto aluminium, is in fact a hologram.

 

[tech99]

The action is the same as a zone plate.