Communicating With Light: From Telephony to Cell Phones

A CIPT Lab Exercise in Modern Physics

Abstract

Abstract

This series of six activities introduces the physics of transmitting "voice" information using electromagnetic signals or light. Students explore how light can be modulated to encode voice information using a simple version of Bell's original photophone. They observe the decrease of the intensity of open- air signals by increasing the distance between source and receiver, and learn the advantage of using materials with different indices of refraction to manipulate and guide light signals. Students are introduced to the concept of bandwidth by using two different wavelengths of light to send two signals at the same time. Finally, students explore how optical signals are manipulated in a photonic chip. 

Appropriate Levels

Appropriate Levels

Physics, Grades 9-12

Time Required

Time Required

Two 80-minutes periods allows time for each of the module's 6 distinct activities to be perormed.

Materials

Materials

For a complete list of materials required, consult the materials section of the lab (which can be displayed by clicking 'here') West Hill Biological has a kit contain all components required to do all six activities that can be viewed by clicking 'here'.

Copyright for this material is held by Cornell University, the Cornell Institute for Biology Teachers (CIBT), the Center for Nanoscale Systems Institute for Physics Teachers (CIPT), and or West Hill Biological Resources, Inc., 2014. This work may be copied by the original recipient from this web site to provide copies for users working under the direct supervision of the original recipient. All other redistribution of this content without the express written permission of the copyright holder(s) is prohibited.

Price: No Charge

Authors:

Jim Overhiser, Cornell University, Ithaca, NY

Luat Vuong, SUNY, Queens College, Flushing, NY