Laser Types and Uses
Laser lights!Copyright lukaszfus, StockXchange (royalty-free image) http://www.sxc.hu/photo/937720
Through two classroom demos, students are introduced to the basic properties of lasers through various mediums. In the Making an Electric Pickle demonstration, students see how cellular tissue is able to conduct electricity, and how this is related to various soaking solutions. In the Red/Green Lasers through Different Mediums demonstration, students see the properties of lasers, especially diffraction, in various mediums. Students will gain an understanding of how light can be absorbed and transmitted by different mediums. Follow-up lecture material introduces students to the mechanisms by which lasers function and relates these functions to the properties of light. In the associated activity, student teams research specific laser types and present their findings to the class.
Biomedical engineers use lasers in diagnostics including optical imaging, which allows for early identification of pathologies. Light's reflected properties must be understood for the use of optical coherence tomography (OCT), in order to create cross-sectional images of the tissue microstructure in an optical biopsy. A focused laser beam shines into the tissue and the echo time delay of the reflected light from the tissues is measured. The image information is obtained, forming a picture that shows the cellular structures in the tissue. Similar to the OCT process, a delay or absence of the laser at the receiving sensor is how the alarm system is triggered for the mummified troll security system. In the post-lesson assessment, students apply the concept of diffraction studied in the second demo and the properties of lasers learned in lecture to understand the mechanism of triggering the alarm.
After this lesson, students should be able to:
- Understand basic properties of lasers.
- Understand how light is transmitted through various mediums
- Develop their own model to test how light will be transmitted through various mediums
- Study and research laser types and their uses.
This lesson also meets the following Tennessee Foundations of Technology educational technology content standards: 2.0, 3.0, 4.0, 5.0, 6.0 and 8.0; see https://www.teta.org/
This lesson also meets the following National Science Education Standards (NSES) teaching standards: A, B, C, D, E, F; see https://www.nap.edu/topic/