S.T.E.M. Store of Canada

Laser Double-Slit STEM Box (includes 12 different "Beam-Splitters")

$50.00

Why Buy From Us?

This new and improved STEM Box includes everything you need to achieve an interference pattern with a laser in less than 60 seconds, like Thomas Young's classic double-slit experiment (we love the following animation of how light is thought to propagate past a double-slit, from: File:Double slit experiment.webm - Wikipedia) :

What's New:

No wire or tape needed
12 different widths of "Beam-splitter"
Hand-crafted from Canadian Maple
Brushed aluminum backing

Included:

(1) Class IIIA, or 3R red laser, serving as a coherent light source. Power of <5mW, and wavelength of ~650nm. Your choice of body colour for the laser (as supplies last).

* Class 3A laser, also known as Class IIIA or 3R laser, is a low-powered laser that emits visible light between 1 and 4.99 milliwatts. It is considered safe when handled carefully, but it may cause eye damage if stared into or viewed with optical devices such as binoculars or microscopes. It is not a skin or material burn hazard. It is the maximum class allowed for laser pointers in the USA and Canada (from Per Chat GPT 4.0, on Mar-24-23).

(2) Double-Slit Assembly, serving as a way to split the coherent laser light beam into a diffraction pattern. Includes 12 very thin wires, from AWG 28 to AWG 50. Handmade in Canada of locally-sourced Canadian Maple. Dimensions are 180mm Length x 31 mm width x 9 mm height. Mass: 41 grams (approx.) (excl. jewel case).

(3) Straight-forward step-by-step illustrated instructions (for an adult) so that you can easily and successfully perform the double-slit experiment at home in less than 60 seconds

(Hint: we find it works best to hold the assembly at least ~1 meter from a wall or other screen, and that anything closer than ~0.5 meters becomes quite difficult to see).

(4) A kid-friendly explanation of the experiment.

Using the materials in this STEM Box, you can see for yourself how different wire widths, distances, orientations, etc. affect the laser interference pattern.

You might also wonder: how does the wavelength of red laser light (about 650nm, or 650 billionths of a meter) compare to the thickness of the 12 different sized wires included in the Assembly (the "beam-splitters")? Table A provides this information, and we've also laser-engraved most of it on each Assembly for easy reference using a Glowforge laser:

We've included in Table A a "Multiple of Wavelength of Red laser light" (far right column) to give users a physical sense of how vanishingly small 650nm really is. We find the tiniest wire (AWG 50) to be barely visible, and yet its 0.025mm thickness is still equal in length to 39 full wavelengths of 650nm red light (!!!).

For a brief demonstration of how the double-slit experiment can be performed at home using a laser, electrical tape, and AWG 32 wire, check out the following video that inspried us early on:

For the truly daring (and make sure you're sitting down for this little dose of reality), check out this video:

And more recently, check out these videos from Fermilab, Answers with Joe, and :

Recommended for Age 12 & Up (with adult supervision)