PHGN 462: Advanced Optics Laboratory

Guest Lecture: Bell Inequality Violation

I delivered a two-hour guest lecture and laboratory demonstration on quantum entanglement and Bell inequality tests. The session covered:

• Theoretical background — EPR paradox, Bell’s theorem, CHSH inequality
• Experimental setup — Type-II spontaneous parametric down-conversion in BBO crystal, coincidence detection with single-photon avalanche diodes
• Data analysis — calculating the S parameter from polarization correlation measurements, statistical significance testing

The lecture drew on my own undergraduate thesis research, where I built a tabletop Bell test apparatus and measured a CHSH parameter of $S = 2.63 \pm 0.07$, violating the classical bound of $S \leq 2$ by over 8 standard deviations.

Student Response

The hands-on demonstration of entangled photon detection was particularly effective — students could observe real-time coincidence counts changing as polarizer angles were adjusted, making the quantum correlations tangible.