Argon Laser
Lens
351 nm
BBO
702 nm
QWP1
QWP2
Double Slit
0.3 mm slit
Filter 1nm BW
D
s
702 nm
D
p
x
Polarizer
(eraser)
path p
path s
QWP quarter wave plates
Without QWP1, QWP2, and polarizer, yields standard Young interference pattern at Ds..
With QWP1 and QWP2 but without polarizer, there is no interference pattern at Ds.,
With polarizer set to angle of QWP1, Ds yields interference pattern, and with it setat the angle of QWP2, it yields the interference antifringes.
Walborn, Cunha, Padua, and Monken, Double-slit quantum eraser
Physical Review A, Volume 65, 033818