Diffraction of Light

Objectives-

Conceptual: To study the wave properties light, specifically diffraction.

Experimental: Use the Light Sensor to measure the intensity of the maxima in a double-slit diffraction pattern and a single-slit diffraction pattern created by monochromatic laser light passing through a double-slit and a single slit. Use the Rotary Motion Sensor (RMS) to measure the relative positions of the maxima in the diffraction pattern.

Prediction Questions:

Question 1: Draw a pencil shading sketch of what you think diffraction pattern will look like.

Question 2: A diffraction pattern has regions of varying intensity. Sketch a graph showing how intensity varies with time.

Question 3: A single light source is what causes the diffraction pattern that is spread out over space. How does the intensity of the diffraction pattern change as you move away from the light source does it increase, decrease or stay the same?

Analysis Question:

Question 1: The light and dark bands are caused by the same light interfering, what is happening in the light and dark regions that are making them different? What's happening in between the brightest and the darkest regions where it is not completely dark or bright?

Question 2: As the slit width increases how would the diffraction pattern change in appearance? Justify your answer.

Question 3: Examine the Graph display of Light Intensity versus Position for both the double-slit and the single-slit patterns. How does the plot of light intensity versus position for the double-slit diffraction pattern compare to the plot of light intensity versus position for the single-slit diffraction pattern?

Question 4: Write a description comparing the single and double slit plots with what they physically correspond to in the actual diffraction pattern in terms of: physical significance of the peaks, height of the peaks and variation in intensity of the peaks.