Hands-on Activity Lasers, Let's Find 'Em!

Learning Objectives

After this activity, students should be able to:

• Identify types of lasers and their functions.
• Describe laser applications in today's world.
• Select the most appropriate laser for the security system design.

This activity also meets the following International Society for Technology in Education (ISTE) standards: 1.1, 2.1, 2.2, 2.3, 3.1, 3.2, 4.1, 4.2, 5.1, 5.2, 5.3, 6.1, 6.2; see  https://www.iste.org/standards

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

Materials List

Each group needs:

• computer with Internet access
• word processing software, such as Word, Open Office, etc.
• presentation software application, such as Microsoft PowerPoint
• (optional) video cameras and video-editing software application, such as Movie Maker, I-Movie, etc.
• blank copy paper and markers (for groups that choose the option of making brochures)
• Laser Research Form, one per group per student (cut each sheet in half to create two forms)

Worksheets and Attachments

Pre-Req Knowledge

Students should have a basic understanding of light properties, how lasers work and how excited matter emits different color photons, as provided in this unit's lessons 2 and 3: Learning Light's Properties, and Laser Types and Uses (which includes the Making an Electric Pickle demo and Red/Green Lasers through Different Mediums demo).

Introduction/Motivation

What types of lasers can you name? From what we explored in the Making an Electric Pickle demo (see Laser Types and Uses lesson), what do you know about chemical compounds and their affect on color? Do you think there is a relationship between laser names and the chemical compounds associated with the type of radiation they emit? Have you ever heard of a HeNe laser, or how about an argon laser?

In today's activity, we will explore the various types of lasers, why they are named what they are named, and what their uses are in science and technology today. After researching your assigned laser type, you will create a PowerPoint presentation, a small film clip, or a pamphlet to present to the class. At the conclusion of the presentations, each of you should be able to select the most appropriate laser to be used in the mummified troll security system. Further, you should each understand how lights' properties in various mediums enable the system to detect movement near the troll.

Procedure

Before the Activity

• Have available enough computers with Internet access, as well as presentation, word processing and/or video editing software applications.
• Gather materials and make copies of the attached Laser Research Form, one per student per number of groups, for students to take notes on during the presentations. Each student may need several forms, depending on the number of presentations.

With the Students

1. Describe the assignment to students.
2. Divide the class into teams of two or three students each.
3. Assign each group a laser type to research. Laser types: helium neon laser, argon laser, ruby laser, carbon dioxide laser, oxygen iodine laser, M-THEL (mobile tactile high energy lasers), etc.
4. Give enough time for students to find information and create presentations. See the questions listed in the "Investigating Questions" section below. Make sure students address each of these in their presentations. In addition to creating their presentations, have students type a report of their findings that they turn it in at the end of their presentations. 
5. After about 50 minutes of research and presentation preparation, begin the class presentations.
6. Direct students who not presenting to take notes using the blank forms.

Vocabulary/Definitions

laser: A device that emits coherent light through a specific mechanism. An acronym for light amplification by stimulated emission of radiation.

Assessment

Activity Embedded Assessment

Participation Grade: Consider students' presentations and group contributions in formulating their daily participation grades.

Investigating Questions

Students need to address each of the following in their presentation of the laser type they researched:

• Name/type of the laser.
• Review how a laser works (use technical terms from the lesson).
• What does this laser look like?
• What does the laser do?
• How is the laser used? Why is this laser particularly useful in these scenarios. In other words, what makes it better than other lasers for that particular function? Also, what makes the laser you researched unique compared to the other lasers you learned about?
• How has this laser affected inventions and innovations with other technologies?

Activity Extensions

Extension Question: After the students have seen each presentation of each laser type, have the students compare lasers that were presented. To help get this going, here is an example. This extension activity is intended to make the students think critically about which laser type would be best suitable for a given scenario.

You are mechanical engineer looking to cut through glass. You know that the smaller the wavelength is of the laser, the more suitable it is to cut through metallic materials. There are many lasers that could help you cut through glass, but there are only two lasers that are accessible to you and commonly available in the market:

• CO₂ lasers. A type of gas laser that is driven electrically and has a wavelength of about 10.6 micrometers.
• Fiber lasers. A solid state laser supplied energy via pump diodes with a wavelength of about 1.064 micrometers.

Which laser would you choose and why? What type of project might the other laser be suitable for? [Answer: The CO₂ laser (and other gas lasers) are typically used for wood, acrylic, glass, paper, plastics, leather, etc. – most materials besides metal. The fiber laser is used for metals and plastic generally.]

Guest Speaker: If students show an interest in one or more types of lasers, contact local university, college or industry organizations to inquire if someone can bring one for a classroom demonstration.

Activity Scaling

• For lower grades, provide more time for research and compilation of information.
• For upper grades, allow less time for research and compilation of information, as might be the case in the real-world with deadlines and time limitations.

References

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.