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Quantum eraser

Product No: P2220800

Principle

A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarization filters with opposite polarization planes are placed in the two interferometer paths the interference patterns disappear. Placing another polarizer before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described both in terms of propagating waves, as well as particles (photons). The experiment illustrates this duality by showing how interference patterns can be explained on the basis of both classical wave mechanics and quantum physics.

Tasks

Set up the experiment and observe the interference pattern on the screen.
Change the polarization of the beams with the PF1 and PF2 polarizers and observe the influence on the interference pattern.
Use the third polarizer PF3 to cancel the polarization of the light in the two beams, and observe the reappearance of the interference pattern.

What you can learn about

Wave-particle duality
wave interference
quantum mechanics.

Materiallist (Excerpt)	Product	Amount
Laser, He-Ne, 0.2/1.0 mW, 230 V AC	08180-93	1
Optical base plate in exp.case	08700-01	1
Diaphragm holder f.opt.base plt.	08724-00	1
Polarizing filter f.opt.base pl.	08730-00	3
Adjusting support 35 x 35 mm	08711-00	4
Polarization specimen, mica	08664-00	1
Surface mirror 30 x 30 mm	08711-01	4
Beam splitter 1/1,non polarizing	08741-00	2
Holder f. diaphr./beam splitter	08719-00	2
Lensholder f. optical base plate	08723-00	1
Magnetic foot f. opt.base plt.	08710-00	13
Lens, mounted, f +20 mm	08018-01	1
Screen, white, 150x150mm	09826-00	2