How does the diffraction grating in Canadian currency work?

[Paddyster]

Hi,
This is my first post so apologies if I'm not clear enough or if I am posting in the wrong place. I am doing my 3rd year project at university and I am creating diffraction gratings. My supervisor shown me a Canadian note and if you shine a laser through the maple leaf it will shine on the other side as the number value associated with the note. I was hoping to produce something similar for my project but for it to emit my initials instead of numbers. Does anybody know how I'd go about this?
Kind regards.

 

[.Scott]

I'm thinking "computer generated holography".
https://en.wikipedia.org/wiki/Computer-generated_holography

For your output device, use that 600dpi printer you mentioned in an earlier post and then scale it down photographically.

 

[Andy Resnick]

Hi,
This is my first post so apologies if I'm not clear enough or if I am posting in the wrong place. I am doing my 3rd year project at university and I am creating diffraction gratings. My supervisor shown me a Canadian note and if you shine a laser through the maple leaf it will shine on the other side as the number value associated with the note. I was hoping to produce something similar for my project but for it to emit my initials instead of numbers. Does anybody know how I'd go about this?
Kind regards.

It's a transmission diffractive optical element: because it's a phase grating, not an amplitude grating, you can't (conventionally) print one. The company, Innovia Security, apparently has a whole suite of related technologies:

https://www.innoviasecurity.com/uploads/pdfs/Security-Features-Reference-Guide-EN---Final.pdf
https://cclsecure.com/uploads/pdfs/Specimen-Issue-1-EN-web.pdf
http://demo.icpress.ru/en/demo/countries/47/single_banknote/12004.html