Laser Web

In teaching about the behavior of light, the laser is one of the most dramatic and effective teaching tools. The cost of lasers has come down significantly in recent years, to the point where colored lasers that were once extremely expensive can now be purchased quite reasonably.

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In teaching about the behavior of light, the laser is one of the most dramatic and effective teaching tools. The cost of lasers has come down significantly in recent years, to the point where colored lasers that were once extremely expensive can now be purchased quite reasonably.

Our new unit emits a brilliant, crisp beam of green amplified light. Our first use here is a simple illustration of Hero’s Law of Reflection. After firing the laser at a mirror, we use atomized water to scatter the laser beam. Our camera is able to film the laser beam as it interacts with the microdroplets of atomized water. You can see in the film that the angle at which the laser strikes the mirror in our dark lab is the same as the angle at which the reflected ray bounces back. You could measure the angles of incidence and reflection using an oversized protractor similar to those used when drawing geometric figures on a white board during a math lesson. Alternatively, you can take a digital photo of the laser beam’s reflection from the mirror (disable the flash on your camera) and then calculate the angles from the photo.

While canned stage fog can be used to “visualize” the laser, we prefer atomized water because it’s less expensive and odorless. Stage for is more effective for some experiments because it remains suspended in the air, allowing more time to interact with the laser beam. We do not recommend using chalk dust or any other airborne particulates to scatter the laser beam because of the risk of triggering asthma attacks and respiratory problems.

We plan to add other laser experiments with our new green laser unit in the near future.