Lab 6: Double-slit interference and single-slit diffraction Name: Homework 1. Open this simulation: https://phet.colorado.edu/sims/html/wave-interference/latest/wave-interference_en.html . Click on "slits". You have three choices, water waves, sound and light. o Chose the light tab. Make sure both "screen" and "intensity" are checked. Choose "Two slits" with the smallest possible slit width of 200 nm. . . Set the amplitude to a maximum and keep the frequency right in the middle (green light). Leave the barrier in the default middle position. (a) What is the distance from the central bright fringe to the closest dark fringe? (b) What is the distance from the central bright fringe to the next bright fringe? Note that you can grab and drag the measuring tape from the top right in the simulation in order to make distance measurements. 2. Use the above information to determine the wavelength of your green light source. 3. Now increase the distance between the screen and the barrier by 1500 nm (You can click on the two-sided arrow below the barrier and then drag it to the left and right). How does the distance between the bright spots change? Determine the wavelength again using the new setup. 4. Suppose that the distance between the slits were increased. Would the pattern "spread out" or become "more compact?" After you have made your prediction, check by increasing the separation. Change the separation between the slots to 2000 nm, measure the distances and determine the wavelength.Prelab 5: Double-slit interference and single-slit diffraction Name: Light from a laser passes through two very narrow slits as shown in the top view diagram at right. The Y Z photograph shows what appears on a screen that is far Pattern from the mask. The screen is bright at points X and Y on and dark at point Z. screen If the left slit were covered, would the brightness at each of the following points increase, decrease, or stay the same? Explain. Point Y Point Z 2. Suppose that the distance separating the slits is changed (without changing the width of the slits). Original patter The new pattern on the screen is shown at right. on screen a. Was the slit separation increased or decreased? New pattern Explain. on screen Center of screen b. Suppose that, instead of changing the slit separation, the wavelength of the laser light was changed. The effect on the pattern is identical to that shown above. Was the wavelength increased or decreased? Explain