Lenses

Optics II

In this course, Professor Charles Adams (Durham University) follows from his Optics I course and provides a more advanced account of optics. In the first mini-lecture, we discuss lenses, this time going into more depth by first deriving the thin lens equation and then looking at the additive property of the optical power of lenses. In the second mini-lecture, we revisit refraction, derive the Law of Ibn Sahl (also known as Snell’s Law), and introduce the concepts of the critical angle and total internal reflection. The third mini-lecture introduces the polarisation of light, including historical context on the development of polaroid sheets, as well as two demonstrations that involve light propagating through sugar syrup and a polaroid sheet. The fourth mini-lecture delves into the quantum aspects of light, introducing topics such as wave-particle duality, quantum technology, Young’s double slit experiment, the Heisenberg microscope, and complementarity.

Lenses

In this mini-lecture, we revisit lenses, focusing in particular on: (i) the thin lens equation that relates the focal length, the distance from the object to the lens, and the distance from the lens to the image; (ii) deriving the thin lens equation using geometry; (iii) two ways to change the optical power of a lens: by changing the refractive index or by changing the radius of curvature of the lens; (iv) the additive nature of lens power; and (v) two exercises on lenses.