Geometric Optics

Geometric Optics

Law of reflection:

• The angle of incidence equals the angle of reflection.

Diffuse reflection:

• Reflection from a rough surface where variations in the direction of the surface cause light to reflect in different directions.

Convex mirror:

• Also called a diverging mirror, a surface that diverges light as if it originates from a point behind the mirror, a focal point.

Concave mirror:

• Also, called a converging mirror, a surface that converges light to a single point, focal point.

Real image:

• An image where the rays of light actually meet at a location.  It can be projected onto a screen.

Virtual image:

• An image that cannot be projected onto a screen.  The rays of light don’t actually converge there, they just seem to originate from that location.

Refraction:

• The bending of light due to its change in velocity in various media.

Index of refraction:

• The ratio between the speed of light in a vacuum and a particular medium.

Snell’s law:

• The formula that describes the amount of refraction of light based on the two different media and the angle of the light ray:  n1sinθ1=n2sinθ2

Total internal reflection:

• The complete reflection of light when it strikes the boundary between two media at greater than a critical angle.

Convex lens:

• A converging lens that gathers incoming light to a single focal point.

Concave lens:

• A diverging lens that diverges light as if it originates from a point behing the lens, the focal point.

Spherical aberration:

• A lens defect where light is imperfectly focused near the focal point.

Chromatic aberration:

• A lens defect where various color focus at different locations.