# Wright State University Lake Campus/2019-1/diffraction

## Abstract

This paper was written as part of the lab component course in two classes. The first lesson the class learned was how to use Google scholar to properly reference an article.

## Motive

This is a lab about using two equations to solve for two unknowns. One unknown is the wavelength of a helium neon laser. The other unknown is the width of a slit a single slit diffraction experiment. However we did not solve for the second unknown, being that it was so small that we didn't have the equipment to measure it.

## Theory

### Telescopes

Section written by Phy1060:

The eye perceives parallel rays as coming from very far away from a star.

Fig A:  Telescope is looking directly at a star the two lenses bend the rays so they cross. One big advantage is that the energy is compressed into a smaller area at the eyepiece. The lens' job is to take in thelight from a distant star and bend the light to make the star seem brighter to the eye, as shown in Figure A, where you can see how the light's energy is concentrated from the area of the large objective to the size of the smaller eyepiece. 

In figure B, we now imagine offset by an angle alpha form the original star.  This telescope also increases the apparent magnitude of the angle (n orther words beta>alpha). The ratio beta/alpha is known as the angular magnifation.

### Refraction

Huygens' principle lets us treat wave propagation by considering every point on a wave front to be a secondary source of spherical wavelets.

### Mathematics

This report will focus only on an approximate formula that describes single slit diffraction for a screen that is far from the source, and at angles that are sufficiently small that:

${\frac {y}{x}}={\frac {\lambda }{w}}$ We have four variables:

$\lambda =\lambda _{0}$ $x=x_{0}$ $y=y_{0}$ $y=y_{1}=y_{0}+\Delta y$ $w=w_{0}$ $w=w_{1}=w_{0}+\Delta w$ Four observations can be made using these variables: $x_{0}$ , $y_{0}$ , $y_{1}$ , and $\Delta w=w_{1}-w_{0}$ .