1. Jan 16, 2013

### mishima

I was hoping to make a great hands on optics experience this semester for my small (9) class of 11th and 12th grade (high school) students. My own experience was a bunch of ray diagrams and I would like that to not be the only thing going on here. This course is the only physics course at our school and consists of all honors students. Things considered in the realm of engineering/design are welcome, they really respond when we do Science Olympiad events in class.

Specific Questions:
• What kind of laser should I buy?
• What are some fun optics activities that have worked for others in the past?
• What hasn't worked well for others?

Thanks for any input.

2. Jan 16, 2013

### Simon Bridge

For high school - buy second hand lasers off a university if you can.
Experiment with laser pointers if they are legal where you are. Pointers tend to spread out quite a bit so you may need to use a lens - if you do the lens part first, you can give that as an exercize for the students (where to put the lens to get parallel light out of the laser).

Break out the schools collection of lenses and see what they will do.
A good rig for lenswork is to use a 12V halogen lamp with a translucent plastic sheet over it as an object (you can draw a figure - not an arrow - on the sheet).

There is a lens you won't have which you should make - get someone to make you four small spherical sheets - so the glass is the same thickness all the way but concave on one side and convex on the other side, you know, a section from a spherical shell.

Mount two of concave-side together to make a biconvex lens, and two convex side together (leave a little gap) to make a bi-concave lens. After getting students to investigate the solid glass lenses (showing them how to characterize a lens as "converging" or "diverging" - finding the focus etc. All of which can be done without ray diagrams if you like) get them to investigate the special set you just made :)

If you are careful you can get the special lenses make to have a similar focal length to the corresponding solid lenses. (They usually work better than solid glass lenses and you can make them any size you can afford).

If your school can afford it - a very large concave mirror, as big as you can get, and hang it on the wall. Virtual images are difficult for students to "get" in a small setup.

3. Jan 17, 2013

### Andy Resnick

I used this kit as part of a lab:

http://www.litiholo.com/

It's amazingly easy to use and the students get to keep their hologram. Some students investigated hologram 'quality' as a function of illumination conditions, object color, etc. etc. One group demonstrated the hologram as a memory device by figuring out how to record multiple holograms on the same film and selectively displaying a single hologram.

There's loads of great background information as well- what a hologram is, how to record one, what applications....

4. Feb 5, 2013

### mishima

Thanks, I ordered the litiholo kit, that sounds memorable.

I got a set of cheap ($5) eyepieces for watchmaking to rip lenses out of. Then I just bought normal square glass mirrors at a hobby store and intend to convert them into front surface mirrors using paint stripper on the back. I have a large acrylic equilateral prism. Only thing missing is convex/concave mirrors, and concave lens. Not sure where to get those on the sly. I also need an easy way to make a decent lens holder. For lasers, I ended up getting a cheap "astronomy" pointer as well as a$20 Craftsman laser level. Why the craftsman? It has a fan shaped laser which makes doing things like taping down a piece of paper and tracing out rays with pencil/protractor easy. I just use black office binder clips to make the mirrors stand up.

I would like to try the halogen lamp setup Simon Bridge mentioned, but am not sure what you mean. Can you show me a picture of the type of halogen lamp you are talking about?