**A. Single Slit**

*As the width of the single slit increases, describe how the intensity pattern changes:*

As the width of the single slit increased, the width of the maxima/minima decreased, the distance between the maxima/minima decreased, and the intensity of the central maxima increased.

*How does the intensity pattern change from a change of longer wavelength to shorter wavelength for a single slit?:*

As the wavelength decreased, the central maxima became narrower, and the maxima/minima became closer together (i.e. the spacing decreased).

**B. Double Slit**

*Compare the intensity pattern of the double slit to that of the single slit. Which features of the pattern result from single-slit diffraction and which from two-slit interference?:*

The dropoff in intensity from the central maxima is a direct result from the diffraction of the single slit whereas the "dot" nature of the maxima/minima interference pattern is unique to the double-slit interference pattern. While the single slit has a diffraction pattern that looks diffuse across maxima/minima that may be stretched out, the double slit pattern has within these maxima stronger portions of intensity.

*As the width of the double slit increases, describe how the intensity pattern changes:*

As the width increases, the overall intensity increases since the distance between the maxima and minima decrease and the width of the maxima/minima decrease as well.

*How does the intensity pattern change from a change of longer wavelength to shorter wavelength for a double slit?*

As the wavelength decreases, the overall intensity increases, the maxima and minima become closer together, and their widths become smaller.

**C. Diffraction Grating**

*Compare the intensity pattern of the diffraction grating to that of the double slit. Why is a multiple slit grating better than a two-slit grating for making accurate determination of wavelength?*

There are far fewer maxima/minima than in the double slit experiment and they are a lot more pronounced and well-defined dot patterns. Diffraction gratings are better than two-slit gratings for making determinations of wavelength precisely because the maxima and minima become very far from each other making it easier to measure between the maxima.

*As the spacing of the diffraction grating increases, describe how the intensity pattern changes:*

As the spacing increases, the width of the maxima/minima decreases, and the overall intensity of the central maxima increases with an increased focus to the center.

*How does the intensity pattern change from a longer wavelength to a shorter wavelength for a diffraction grating?*

The distance between the maxima decreases and the overall intensity of the central maxima increases with an increased amount of focus.

**D. Wavelength Determination**

*Calculate the wavelength of the red laser using the intensity pattern of the diffraction grating:*