Trivia Question Which “Big Bang Theory” character is an Optical Physicist? (a) Sheldon Cooper (b) Leonard Hofstadter (c) Howard Wolowitz (d) Raj Koothrappali (e) Amy Farrah Fowler d c a e b

The grand overview of Optics/Photonics Historical Development: Ray Optics → Wave Optics → EM Optics → Quantum Optics. We will cover only CLASSICAL Optics in this course. EM Optics is the most general for optical phenomena which can be explained classically. Wave optics is a SCALAR approximation of EM Optics Ray Optics is an approximation in which wavelength short (Diffraction ignored).

Postulates of Ray Optics Light travels as Rays Medium characterized by refractive index n For inhomogeneous medium, the time taken for light to travel from A to B is proportional to optical path length Fermat’s Principle – Light rays travel along the path to minimize the transit time.

Law of Reflection NOTE: If reflection point were NOT in plane of incidence, path length from A to mirror, to C would increase. Would violate Fermat’s Principle.

Law of Refraction

Optical Components - Mirrors Paraxial approximation – (first-order optics or Gaussian Optics) incoming rays to optical component make small angle with respect to optical axis. R<0 for concave mirrors. R>0 for convex mirrors. ZoZo ZiZi

Total Internal Reflection

Spherical Boundaries For a complete lens, the image of the first boundary becomes the object for the second boundary. There are standard sign conventions for R’s and z’s….

Example: Spherical Aberration Chromatic Aberration: If the refractive index n depends on COLOR of light, different colors of light will focus at different locations. Week1-spherical-aberration

Rays and Wavefronts Rays are perpendicular to wavefronts: wavefronts denote surfaces of CONSTANT phase

Parabolic Slab

‘Rigid’ light relay structure - Borescope Flexible Endoscope with Fiber-optic bundle

Exercise 1.3-1