Introduction to Quantum Mechanics I Lecture 1

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[yevgeniyterekhin]

Approximately at 1:33, the diagram is confusing. You use a bold doubled (pointing in both directions) arrow to represent the polarization of the light. Why don't you just use ONE doubled thin arrow to represent the orientation of the polarizer or, as you call it, PBS? When the the orientation of the PBS is "aligned" with the vertical polarization of the light, the doubled bold and the thin arrows are both drawn vertically. PBS + output shows 100% and - output shows 0% in this scenario. When the PBS is rotated 90 degrees relative to the vertical polarization of the light, your draw the doubled bold arrow vertically and the the doubled thin arrow horizontally. The PBS's + output shows 0 % and the - output shows 100% in this case. Why are you using one bold arrow and two thin arrows in the diagrams?