1. Diffraction- Use the laser pointer from the lab to measure the width of one of your hairs.To do this you need a hair taped into some sort of frame to hold it steady. You point the laser at it and take measurements of the diffraction pattern.Please photograph or draw your set–up(labeling all distances)as well as the pattern you are measuring and include all your calculations to get full credit. A good video explaining how to do this can be found here: 

2) Two Lens Systems- A converging lens with a focal length of 20.0 cm is located at the origin. A diverging lens with a focal length of 10.0 cm is located 15.0cm away to the right. You can use your kit to check your answers.

a) Light from a very, very far away object is incident from the left of the converging lens. Find the location and magnification of the image and determine whether it is real or virtual.

b) Light from a very, very far away object is incident from the right of the diverging lens. Find the location and magnification of the image and determine whether it is real or virtual.

3. Thin Films- You are designing a dielectric mirror that uses thin-film interference to provide extremely high reflectivity for a laser that has a wavelength of 785 nm. You have a bunch of diamond panels(n=2.4)you can use for the back part of your mirror. For the thin film, there are two materials you can choose from –Compound X, with refractive index 2.6, and Compound Y, with refractive index 2.2. Both compounds are outrageously expensive, and so you need to decide which to use to minimize the expense.

a) What is the thinnest film you can use to provide strong reflection from Compound X?

b)What is the thinnest film you can use to provide strong reflection from Compound Y?

c)Which compound should you choose and why?