Single Photon Interference

at Hobart and William Smith Colleges dept. of Physics

Fall 2019

The wave-particle duality of light has been investigated in a variety of ways. This experiment seeks to show a wave property of light, diffraction, with quantized particles of light, thus showing that light behaves both as a wave and a particle.

A high-intensity laser and a filtered incandescent light were used as nearly mono-chromatic sources. Both sources then were put under single and double slit diffraction. The intensities were then measured in finite widths across appropriate detectors for each source: a photodiode for the laser and a photomultiplier (PMT) for the incandescent bulb.

The PMT is able to measure the rate of individual photons arriving at the detector. With a known chamber length, it can be shown that each photon is traveling one at a time, and still producing a diffraction pattern.

Below the paper of the result can be found.

A plot showing the double slit diffraction data collected (blue) and the fitted Fraunhofer diffraction pattern (red). The source was a incandescent bulb that was dim enough for single photon emission.

Single Photon Interference Paper

James Monaco

Electrical Engineering BE, Dartmouth '21

Chemistry and Physics BS, Hobart and William Smith '20

contact:

JamesTMonaco@gmail.com

  • Grey Instagram Icon

resume