Results
The operating voltage of the light source was set at 6.01 V. Figure 5 shows the plot for double slit interference pattern, which contains both the measured and theoretical values:
Figure 5. Double slit interference pattern with theoretical prediction: blue dots with error bars are the measured results while the orange curve is the theoretical prediction of double slit interference based on Eq. (4)
The visibility value in this case is 0.495 ± 0.036 , which was calculated using the fitted curves of Imax with reduced χ2 value of 1.03, and Imin with reduced χ2 value of 1.05.
Figure 6. Double slit interference pattern with fitting curves: blue dots with error bars are the measured results while the grey and yellow curves are the fitted results based on Eq. (6) and Eq. (7)
We applied the same method in which-path and quantum eraser experiment. Here are the plots we got for each situation:
Figure 7. Destroyed interference pattern with theoretical prediction: blue dots with error bars are the measured results while the orange curve is the theoretical prediction of single slit diffraction pattern based on Eq. (2)
Figure 8. Restored interference pattern with theoretical prediction: blue dots with error bars are the measured results while the orange curve is the theoretical prediction of double slit interference based on Eq. (4)
The visibility value for both situations is 0, meaning no detectable interference is found. Therefore, the quantum maker reduced the visibility of interference by 100%, but the quantum eraser restored the visibility by 0%.