In this experiment designed for use with PASCO Capstone software, interference and diffraction patterns from laser light passing through various single-slits and multiple-slits are scanned and plotted in real-time. These patterns are then examined for similarities and differences.
The distances between the central maximum and the diffraction minima for a single slit are measured by scanning the laser pattern with a Light Sensor and plotting light intensity versus distance. Also, the distances between interference maxima for two or more slits are measured. These measurements are compared to theoretical values. Differences and similarities between interference and diffraction patterns are examined.
Since the Linear Translator tracks the position of the Light Sensor, it is not necessary to move the Light Sensor at a constant speed. The intensity versus distance graph is plotted in real-time, showing the connection between the intensity pattern and the actual laser pattern.
Adjustment of the slit size on the Light Sensor mask gives the resolution required to see detail in the interference patterns.