top of page
Writer's pictureNeerja Aggarwal

A scotch-tape spectrometer

Updated: Oct 17



Our group published a new study called “DiffuserSpec: spectroscopy with Scotch tape”. Here’s a summary of the paper I wrote for my friends and family (non-technical audience). I was inspired by reading “Optical Physics for Babies” to my nephew the other day. Let’s begin!


Light is made up of many colors. (Think of a rainbow: sunlight gets separated by rain into colors from red to violet ).


It is useful in science to generally know what colors light is made up of, especially when it bounces off objects. It can tell you what the material you are looking at is made of. (This is called reflectance spectroscopy).


Usually to break up light into different colors you have to use a special scientific instrument called a spectrometer that uses a piece of glass called a “grating”. It works similar to rain and creates a rainbow. How bright each part of the rainbow is tells us how much of each color there is.


But what if instead we wanted to use scotch tape or a some other bumpy piece of plastic cause it’s cheaper or just interesting to try? Then instead of seeing a rainbow we would see the light colors scrambled up. We detect these scrambled colors using a camera. Then we solve the puzzle using a computer to “unscramble” the colors and get back the rainbow.


Other scientists have already been using this technique widely. (It’s called speckle-based spectroscopy). But usually they try to make a custom piece of glass or plastic to spread out the light. One study showed you could do it with frosted glass. In our paper, we show you can do it with something cheap and off-the-shelf like tape. It basically worked just as well as the other stuff. (We had also tested a lot of bumpy pieces of plastic you can buy online called “light diffusers” but didn’t include it in this paper).


Hopefully this makes this field of “speckle-based spectroscopy” more accessible for other scientists and not just those with the fancy machines to make the custom pieces.

You can read the full technical journal article here: https://opg.optica.org/ol/fulltext.cfm?uri=ol-48-2-323&id=524687


Enjoy!


28 views

Comentarios


bottom of page