The best examples of light wave experiment examples for real classrooms

Classic examples of light wave experiment examples you can actually run

When people talk about light waves, they often jump straight to theory. Let’s skip the abstract and start with real examples of light wave experiment examples you can do with inexpensive gear.

A laser pointer, a ruler, and a bit of patience are enough to reproduce some of the best examples in wave physics: interference fringes, diffraction patterns, and polarization effects. These are the same ideas that underpin fiber‑optic communication, anti‑glare sunglasses, and even how your phone’s camera works.

Below, each example of a light wave experiment comes with:

• What concept it shows
• What you need
• How to run it in a realistic classroom or home setting
• What measurements students can actually take

Double‑slit interference: the headline example of light as a wave

If you had to pick one experiment to show the wave nature of light, the double‑slit setup is still one of the best examples. It’s dramatic, visual, and surprisingly easy.

Concept: Coherent light passing through two narrow slits produces an interference pattern of bright and dark fringes on a screen.

Gear you actually have or can get cheaply

• Low‑power red laser pointer (≤ 5 mW, Class 2 or 3R)
• Double‑slit slide (commercial, or DIY with razor blades/foil)
• White screen or wall
• Measuring tape or meterstick

How to run it

Darken the room, aim the laser at the double slit, and project the pattern onto a wall several feet away. Students can measure:

• Distance from slits to wall (L)
• Spacing between bright fringes (Δy)
• Known slit spacing (d) from the slide

Using the formula \( \lambda = \frac{d\,\Delta y}{L} \), they can estimate the laser wavelength and compare it with the manufacturer’s spec (usually around 650 nm for cheap red lasers). That comparison immediately grounds the math in a real‑world check.

This is one of the clearest examples of light wave experiment examples that connects a visual pattern to a quantitative wavelength measurement.

Single‑slit diffraction: when one opening is enough

If the double slit is the headline, the single slit is its underrated cousin. It shows that even a single narrow opening produces a diffraction pattern.

Concept: Diffraction and interference from a single aperture; angular width of the central maximum.

Gear

• Same red laser pointer
• Single‑slit slide or a narrow slit cut in aluminum foil
• Screen and measuring tape

What students see

Instead of a simple bright spot, they’ll see a wide central band with dimmer side bands. By measuring the width of the central maximum and the distance to the screen, they can estimate the slit width using \( a \sin \theta \approx \lambda \), where \( a \) is slit width.

This gives another example of a light wave experiment where students can:

• Compare theoretical predictions with actual measurements
• See how narrowing the slit spreads out the pattern

It’s also a nice segue into talking about diffraction limits in microscopes and telescopes—real examples of how wave behavior limits resolution.

Diffraction grating and CD/DVD experiments: turning everyday objects into spectrometers

Diffraction gratings are arguably the best examples of how precision engineering meets wave physics. But you don’t need a lab‑grade grating; an old DVD or CD works surprisingly well.

Concept: Diffraction from many equally spaced lines; resolving different wavelengths.

Gear

• White LED flashlight or phone flashlight
• Old CD or DVD (data side)
• White wall or sheet of paper

How to do it

Shine the flashlight onto the CD at a shallow angle and project the reflected light onto a wall. You’ll see a rainbow spread out. Students can:

• Identify colors corresponding to different wavelengths
• Compare the spread from a CD (larger track spacing) vs. a DVD (smaller spacing)

If you use a known monochromatic source, such as a red laser, and look at the diffracted spots, you can again use the grating equation \( d \sin \theta = m \lambda \) to estimate wavelength.

This is one of the most accessible examples of light wave experiment examples for younger students because it uses familiar objects and doesn’t require a dark room.

For a deeper dive into how diffraction gratings are used in real research, the U.S. National Institute of Standards and Technology (NIST) has accessible explanations of spectroscopy and standards for optical wavelengths: https://www.nist.gov

Polarization with sunglasses and phone screens: waves with a direction

Polarization experiments are fantastic real examples of how abstract wave ideas show up in daily life.

Concept: Light as a transverse wave; selective transmission depending on orientation of the electric field.

Gear

• Two inexpensive polarizing filters (or two pairs of polarized sunglasses)
• LCD screen (laptop, tablet, or phone)
• Bright light source or window

Simple setups

Hold one polarizer in front of your eye and rotate it while looking at an LCD screen. The brightness will vary and may go almost dark at certain angles. Add the second polarizer and explore:

• Maximum transmission when polarizers are aligned
• Minimum transmission when crossed at 90°
• Partial transmission at intermediate angles

Students can record transmitted intensity vs. angle and compare with Malus’s law \( I = I_0 \cos^2 \theta \). This turns into a data‑rich example of a light wave experiment that mixes geometry, trigonometry, and real devices.

It’s also a direct connection to polarized sunglasses and camera filters—examples include glare reduction on roads, water surfaces, and car windshields.

Thin‑film interference: soap bubbles, oil slicks, and anti‑reflective coatings

You don’t need lab optics to see thin‑film interference; you just need a soap bubble or a drop of oil on water.

Concept: Interference between light reflected from the top and bottom surfaces of a thin film.

Gear

• Dish soap and water (for bubbles) or a shallow pan of water plus a drop of oil
• White light source (sunlight, lamp, or phone flashlight)

What to look for

Students observe shifting bands of color as the film thickness changes. This gives a qualitative but powerful example of light wave experiment examples that:

• Shows path difference and phase shifts without equations
• Connects directly to anti‑reflective coatings on glasses and camera lenses

For more advanced groups, you can discuss how manufacturers design coatings with specific thicknesses to cancel reflections at target wavelengths—real examples of wave interference driving engineering decisions.

The University of Colorado Boulder’s PhET project offers interactive simulations of wave interference and thin films that pair nicely with these experiments: https://phet.colorado.edu

Photoelectric effect with modern sensors: from Einstein to your smartphone

The classic photoelectric effect experiment is hardware‑heavy, but modern tools let you demonstrate the core ideas more simply.

Concept: Light as photons; threshold frequency; energy of emitted electrons depending on frequency, not intensity.

Classroom‑friendly approaches

• Use videos and data from modern photoelectric setups where intensity and frequency are varied independently.
• Combine this with a hands‑on LED experiment: measure the forward voltage of different color LEDs to estimate photon energy using \( E = qV \) and connect it to \( E = h f \).

While this is a more indirect example of a light wave experiment, it’s an excellent bridge from wave behavior to quantum ideas. Students see that light is not just a wave; it has particle‑like behavior as well.

For historical context and modern applications, the American Physical Society offers accessible articles on the photoelectric effect and quantum physics education: https://www.aps.org

Smartphone‑based light wave experiments: 2024–2025 classroom trends

Over the last few years, one trend stands out: using smartphones as data‑collection tools. In 2024–2025, many teachers are leaning on phones not just as cameras but as portable photometers and spectrometers.

Here are some real examples of light wave experiment examples that integrate phones:

Measuring intensity vs. distance

Students use a light meter app to record intensity from a small LED or flashlight at different distances. While the inverse‑square law is not purely a wave concept, it ties into wave propagation and energy distribution. They can:

• Plot intensity vs. 1/r²
• Discuss deviations due to reflections, sensor limits, and ambient light

DIY smartphone spectrometer

With a diffraction grating film and a cardboard box, students can build a low‑cost spectrometer that uses the phone camera to capture spectra of:

• LEDs of different colors
• Fluorescent vs. incandescent bulbs
• Sunlight (with appropriate safety precautions and indirect viewing)

This is one of the best examples of how modern, low‑cost tech can extend traditional light wave experiments into more quantitative territory.

For guidance on safe classroom use of lasers and light sources, the U.S. Food and Drug Administration (FDA) provides clear safety information on consumer laser products: https://www.fda.gov/radiation-emitting-products

Designing your own examples of light wave experiment examples

Once students have seen a few standard setups, encourage them to design their own examples of light wave experiment examples using the same core ideas:

• Interference: Can they find other everyday thin films—soap, oil, coatings—that show colors?
• Diffraction: What happens when light passes through a mesh, feather, or hair?
• Polarization: How do different materials (plastic wrappers, stress‑bent acrylic) affect polarized light?

This design‑your‑own approach turns passive observation into active inquiry. It also reinforces that the best examples are often the ones students invent, test, and refine themselves.

FAQ: common questions about examples of light wave experiments

Q: What are some simple examples of light wave experiment examples for middle school students?
For middle school, keep it visual and low‑math. Good starting points include shining a flashlight through a slit cut in cardboard to show diffraction, using a CD to create a rainbow from a white light source, and rotating polarized sunglasses while looking at a phone screen. These examples include clear, visible effects without heavy formulas.

Q: Which example of a light wave experiment best shows interference?
The double‑slit experiment is still the standout example of an interference experiment. If slits are hard to source, thin‑film interference in soap bubbles or oil films is a great alternative—students immediately see colored bands caused by constructive and destructive interference.

Q: How do I choose the best examples for a short lab period?
Pick experiments that set up quickly and produce immediate patterns: a diffraction grating with a laser, a single‑slit or narrow opening, and a basic polarization demo with sunglasses. These are fast, reliable examples of light wave experiment examples that fit into a 45–60 minute session.

Q: Are there real examples of light wave experiments used in modern technology?
Yes. Fiber‑optic communication relies on controlled reflection and interference, camera lenses use thin‑film coatings to manage reflections, LCD screens use polarization, and spectrometers use diffraction gratings to analyze light from stars, LEDs, and chemical samples. These are direct, real‑world extensions of the classroom experiments described above.

Q: Where can I find more detailed physics background for these experiments?
University physics departments often publish open lab manuals with theory and procedures. For example, many U.S. universities host free PDF optics labs on their .edu sites, and resources like PhET simulations from the University of Colorado Boulder offer interactive models that complement hands‑on work.

The bottom line: if you want students to really feel that light is a wave—and sometimes a particle—build your course around these concrete, classroom‑friendly setups. Use them as the backbone of your own examples of light wave experiment examples, and let the equations follow the curiosity.