Laser Lesson Plans

With our laser lesson plans and FREE download of the laser worksheet, your kids will describe how a laser beam is formed, recognize what a laser is and does, and have fun with our hands on projects.

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MatchCard Science Laser Worksheett

Objective: Describe how a laser beam is formed.

MatchCard: Download below.

On this worksheet students:

• Identify what the acroynm LASER stands form
• Explain the characteristic of a laser beam
• Describes 7 steps in the formation of a laser beam inside the crystal.

Print the Laser MatchCard

Click image to go to download.

This is MatchCard #7 of the Technology Unit Study. Find more information on MatchCard Science below.

What Is A Laser?

Laser’s have been with us since 1960, though the theories that spawned the creation of lasers go back to Einstein and Max Plank in the earliest years of the 1900’s.

A laser is a beam of light that has been amplified. This page will describe what a laser is.

All students can do these activities as well as describe the term “laser” at the top of the MatchCard. The next page includes activities that describe the three characteristics of laser beams; these are for older students. The last activity for your oldest students includes listing the order of events that create a liaser beam.

Light Amplification BY
Stimulated Emission of Radiation

Laser stands for light amplification (by) simulated emission of radiation.

Well, that certainly clarified things, right? We can break the phrase down a little further to make some sense of the words.

Stimulated Emission of Radiation

• Stimulate: to excite or activate something
• Emission: release of something (in this case radiation)
• Radiation: electromagnetic radiation

So putting this together, it means that excited atoms emitted - or ejected - electromagnetic radiation.

You may remember from Light & Energy Unit Study that electromagnetic radiation is released from the sun as light and other forms of radiation. Now you know that lasers also release radiation - but a whole lot less than the sun!

Now that we have an idea what the stimulated emission of radiation is, what is meant by light amplification?

Light Amplification

• Amplify: to increase

Putting this all together, a laser is an increase in light that is caused by stimulating (or exciting) atoms so that they emit a greater amount of light

So What Can A Laser Do?

Legend has it that the original designers of lasers called them “a solution in search of a problem.” Here was this really cool technology and until Darth Vader came along, no one seemed to appreciate it. Well no more: here’s a list of things that lasers are used for today.

• CD players
• DVDs
• Bar Codes
• Cut hundreds of layers of fabric
• Used in eye surgery
• Telephone signals
• Dental drills
• Car lights

Compare Laser and Flashlight Beams

Have a little fun comparing the laser beam and flashlight beam. Compare:

• the diameter of both on a wall
• the clarity (clearness) of the beam
• how far the light beam will shine (may have to do this outside at night.)

Explain the difference. In the next section, you will learn the scientific terms to explain the differences.

Three Characteristics of Lasers

There are 3 primary characteristics of lasers that help to differentiate them from light from a flashlight, light bulb, or the sun. These characteristics of lasers are:

• Collimated
• Coherent
• Monochromatic

Collimated

• Collimate: moving in a straight line
• Opposite of collimate: divergence (spreading out)

Unlike the flashlight beam, the laser beam moves in a straight line. That is why the diameter of the flashlight beam was large and fuzzy and the laser beam was small and crisp. That characteristic of going straight in one direction allows the beam to travel further as well.

Compare that to the light beam of the sun or a light bulb which has the characteristics of divergence which means it spreads out in multiple directions. Even the flashlight beam, which is shined in a single direction, has the tendency to diverge. The next characteristic of lasers will explain why the laser remains collimated.

Coherence

• Coherence: consistency

The electromagnetic waves that escape from the the laser crystal are all the exact same frequency. The enlarged picture of the laser beam shows waves that are parallel because they are the same size. Since they are coherent in size, it makes them collimated or move in one direction.

Coherence

• Mono: one in Latin
• Chromatic: color in Greek

Monochromatic means a single color. Lasers are commonly available in red or green. Light & Energy MatchCard #13 explains that color is determined by the frequency of a light wave. Since all the waves coming from the laser are the same size, they are the same color. Therefore, the three qualities of collimated, coherence, and monochromatism are all related to the fact that the light waves emitted from your laser are the same frequency. Before we learn how and why they the laser has only one size of light beam, let’s have a little more fun with the concept of monochromatic.

Monochromatic Designs

The concept monochromatic will mean something different to a designer than it will to a scientist even though the root of the word is the same. For a scientist, monochromatic means the color is all EXACTLY the same. For a clothes designer or interior designer, monochromatic means you have one family of colors. Such as:

• Blue: Light blue, medium blue, dark blue
• Red: pink and scarlet
• Brown: Tan, beige, dark brown

In addition, you can add white and/or black to the color scheme and it remains monochromatic. Do an internet search for monochromatic clothing design.

Laser Waterfall

• Laser pointer
• Empty water or soda bottle

Punch a whole near the bottom of the bottle so water can drain out. Fill the bottle with water and watch the stream of water escape (the larger the bottle, the further out the stream of water.) Repeat, but shine your laser into the stream of water.

How Lasers Are Formed

The 7 steps in the formation of a laser beam are listed on the MatchCard Information Pieces and Answer Key.