Chapter 10: Optics

**Electromagnetic Waves**

Consist of time-varying electric and magnetic fields that oscillate perpendicular to each other and to the direction of propagation of the wave.

**the direction of polarization of the wave**

is the direction in which the wave’s electric field oscillates 

Through a vacuum, all electromagnetic waves travel at a fixed speed

**diffraction**

the alteration in the straight-line propagation of a wave when it encounters a barrier

**Single-Slit Diffraction**

A diffraction pattern will also form on the screen if the barrier contains only one slit.

**The angle of incidence**

angle that the incident beam makes with the normal

**The angle of reflection**

angle that the reflected beam makes with the normal.

**The angle of refraction**

angle that the transmitted beam makes with the normal

Law of Reflection

**Snell’s Law**

states when light enters a new medium (material) it changes speeds and may change directions

**Dispersion**

is when light travels through a material medium which is a variation in wave speed with frequency (or wavelength.

**Index of refraction**

which is n = c/v, should be accompanied by a statement of the frequency of the light used to measure v, since different frequencies have different speeds and different indices.

**total internal reflection (TIR)**

A phenomenon called ____________________________ which for angles of incidence that are greater than *θc,* there is no angle of refraction; the entire beam is reflected back into the original medium.

**Plane mirrors**

have light that’s reflected off of the object strikes the mirror and is reflected back to our eyes.

**Spherical Mirrors**

Mirror that’s curved in such a way that its surface forms part of a sphere.

**Center of curvature**

is the center of this imaginary sphere

**Radius of curvature,** ***R***

is the radius of the sphere

**Focus/ Focal point,** ***C***

it the halfway between the mirror and the center of curvature

**Axis**

is the intersection of the mirror’s optic (its axis of symmetry)

**Vertex,** ***V***

is the mirror itself

**Focal length,** ***f***

the distance from *V* to *F*, equal to one-half of the radius of curvature:

**Concave mirror**

a mirror whose reflective side is *caved in* toward the center of curvature

**Convex mirror**

which has a reflective side *curving away* from the center of curvature

**Ray tracing**

is the geometric approach to identify images formed by mirrors

**Mirror Equation**

**Magnification Equation**

**Converging lens**

converges parallel paraxial rays of light to a focal point on the far side

**Diverging lens**

causes parallel paraxial rays of light to diverge away from a virtual focus, F, on the same side as the incident rays