1. Mark F. Masters and Timothy T. Grove Indiana University-Purdue University Fort Wayne Fort Wayne IN 46805 USA

2.  Our optics class was a very traditional, lecture-based, geometric and physical optics class  Outcome: students went through the motions of doing optics without understanding.  They parroted what they had seen and heard  We had recently completed a successful revision of introductory classes and labs to use interactive engagement.

3. For students to …  have greater conceptual understanding of light and optics  be able to use optics knowledge to solve complex problems  be able to work independently in the laboratory. Ideal for interactive engagement/active learning But: intermediate classes have different demands than introductory classes. How to use Interactive Engagement in this setting?

4.  Answer-making: given object distance d, and focal length of lens f, where is the image located?  Equivalently: if a plumbdaad is 0.413 kerndons, then if I have 7 kerndons, how many plumbdaads?  Two systems consisting of a point source, a lens and a screen. In each system, the point source is located on the optic axis 10 cm from the lens which has a focal length of 15 cm. One of the lenses is a diverging lens and the other is a converging lens. The lenses are the same diameter. The screen is located 10 cm away from each lens. Which system will produce the higher average irradiance on the screen?

5.  Students passive in classroom – listen to a lecture, see particular derivations for optics, see worked examples.  Students are nominally active at home through reading book and doing homework.  Laboratory exercises (supposedly)

6.  Concepts: Students wrestle with the material both in class and out  Students must engage in sense-making rather than answer making.  Community: Students work in peer groups to help each other learn the physics (and math).  Communicate: Group and class discussions with instructor as facilitator (not an information source) to assist in building solutions.  Responsibility: Students are responsible for their own learning. Instructor can assist, but not “learn ‘em”!

7.  Nature of light and Models of light  Geometric optics ◦ Ray-tracing, interpreting ray diagrams ◦ Traditional geometric derivations ◦ Optical systems ◦ Aberrations ◦ Point and extended sources ◦ Mathematical Formalism  Physical Optics ◦ Mathematical wave formalism for light and Maxwell’s equations. ◦ Polarization ◦ Interference

8.  Have the students understand: waves, ray diagrams, geometric optics.  Have the students be able to solve complex optics problems  Have the students be able to understand derivations: how to do them, what approximations are made.

9. There are three distinct types of classroom activities:  Conceptual activities, interactive lecture demonstrations  Derivation activities  Application activities

10.  Students often misinterpret diagrams of wave, imagining that the amplitude corresponds to spatial extent of the wave. A B C D E Cartoon snapshot of wave traveling to left

11.  Consider the sound wave shown for two different times (  t=0.3ms). Sketch the waveform at each time and determine the frequency, wavelength and speed of the wave. Position # particles/volume Position # particles/volume

13. h  s   R s’ ’’  small Students are lead through deriving a result Students have to do the work, figuring out the math, etc rather than simply see it performed.

17.  We applied active learning approaches in lecture intermediate optics course  The class uses tutorials and interactive engagement to develop student understanding and sense-making capabilities  These materials are available at http://users.ipfw.edu/masters/ http://users.ipfw.edu/masters/  We acknowledge the support of the U.S. National Science Foundation.