Optics Glossary

An imperfection in an optical system where light rays fail to converge to a single focus point, causing blurred or distorted images.

The maximum displacement of a wave from its equilibrium position, related to the brightness or intensity of light.

The angle of incidence at which reflected light becomes completely polarized, given by tan(theta) = n2/n1.

A fixed phase relationship between waves, necessary for sustained interference patterns.

The process of aligning light rays to be parallel, reducing divergence. Lasers naturally produce well-collimated beams.

A curved mirror with the reflecting surface on the inner side of the curve, capable of focusing parallel light to a real focal point.

A curved mirror with the reflecting surface on the outer side of the curve, always producing virtual, diminished, and upright images.

An optical component with a periodic structure of closely spaced slits or grooves that splits light into its component wavelengths.

The phenomenon where the refractive index of a material varies with wavelength, causing different colors to separate.

A transverse wave consisting of oscillating electric and magnetic fields perpendicular to each other and to the direction of propagation.

The distance from a lens or mirror to the point where parallel rays of light converge (or appear to diverge from).

The number of wave cycles passing a given point per second, measured in hertz (Hz). Related to wavelength by v = f times lambda.

A technique for recording and reconstructing three-dimensional images using the interference of coherent laser light.

A dimensionless number that describes how fast light travels through a material relative to its speed in vacuum (n = c/v).

The superposition of two or more coherent waves, resulting in regions of reinforcement (constructive) and cancellation (destructive).

A device that produces coherent, monochromatic, and collimated light through stimulated emission of radiation.

The ratio of image size to object size. Positive magnification indicates an upright image; negative indicates an inverted image.

Light consisting of a single wavelength or color, as opposed to polychromatic (white) light.

A thin, flexible strand of glass or plastic that guides light using total internal reflection for telecommunications and sensing.

The quantum of electromagnetic radiation; a massless particle of light carrying energy E = hf.

An optical filter that transmits light vibrating in one plane while blocking vibrations in all other planes.

The bouncing of light off a surface, governed by the law that the angle of incidence equals the angle of reflection.

The bending of light as it passes between media of different optical densities, governed by Snell's Law.

The concept that light and matter exhibit both wave-like and particle-like properties depending on the experimental context.

The distance between successive crests (or troughs) of a wave. For visible light, ranges from about 380 nm (violet) to 700 nm (red).