NWU-OSA Outreach Program

NWU-OSA Student Outreach



The NWU-OSA Student Chapter has initiated a program with local high schools in order to foster interest in optics and related sciences. By visiting high schools and giving hands-on demonstrations of optical devices and phenomena we hope to encourage youths to consider the field of optics as a professional career.

In 2000 we traveled to 4 different schools in the Evanston, IL area and visited with over 500 2nd through 9th grade students. Ten active members of our chapter contributed to our success in this area during the past year. This year we hope to continue our tradition and visit at least 3 more schools. The chapter's outreach activities were recently recognized in an article in the Northwestern University Observer.

The program usually consists of three or four stations that students rotate between throughout the course of a class.

Station 1: "Analog and Digital Optical Communications"

This free space optical link demonstrates the basics of optical communications. We directly modulate an LED with the signal from a CD player. The signal is sent via the optical beam to a detector that receives the signal. The signal is then sent to a set of amplified speakers so music and be heard. Students can block the beam or misalign the optics and observe the effect on the system. In addition to the audible signal, the electrical signal is displayed on an oscilloscope so the students can observe its analog nature. Using a normal TV remote control, we detect this digital signal so that it can be heard in a set of headphones and observed on an oscilloscope. With this combination of demonstrations students can learn how the devices around them work, and begin to understand the difference between analog and digital signals.

Station 2: "Optics in the Fish Tank and Jell-O Optics"

A fish tank, flashlights and laser pointers are used to demonstrate refraction, reflection, and total internal reflection (TIR) at the surfaces of water in the fish tank. We have also drilled a hole on one end of the fish tank so the student can see how laser light is guided by the water spilling through the hole. To further investigate how TIR is used we make thick, clear gelatin and cut it into various shapes to show the principles of waveguiding and fiber optics.

Station 3: "Lenses, Imaging and Theta-Modulation"

Using a white light source, transparent objects, and various lenses we can demonstrate the basics of imaging using lens systems. Students get a hands-on basic understanding of image transformation by thin lenses. We have also acquired a special diffraction grating that allows us to perform a colorful demonstration of diffraction and the information processing capabilities of a "four-f" optical system.

Station 4: "The Optics Discovery Kit"

We have found that students that are not excited by guided demonstrations often respond nicely to unstructured "discovery" time. We have purchased classroom Optics Discovery Kits and allow students to experiment with the pieces of that kit in a lightly supervised setting. The kit includes holograms, lenses, diffraction gratings, and color filters. We also have a Moire kit which many students find stimulating.

Further Information

For information on how you can set up your own demonstrations, please contact Jay Sharping. In addition, check out the back issues of Optics and Photonics News, which has simpler and elaborate demos in each issue!
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November, 2000
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