optics

Introduction
Geometrical optics
- General considerations
  - The optical image
  - Historical background
    - Light rays, waves, and wavelets
    - The pinhole camera
    - Resolution and the Airy disk
    - The Rayleigh limit
- Reflection and refraction
  - Reflection
  - The law of refraction
  - Dispersion
  - Total internal reflection
- Ray-tracing methods
  - Graphical ray tracing
  - Trigonometrical ray tracing
- Paraxial, or first-order, imagery
  - Magnification: the optical invariant
  - The Gauss theory of lenses
  - The thin lens
  - Chromatic aberration
  - Longitudinal magnification
  - Image of a tilted plane
- Optical systems
  - System components
    - Lenses
    - Mirrors
    - Light sources
    - Detectors
    - Projection screens
    - Reflecting prisms
    - Dispersing devices
    - Filters and thin films
    - Fibre-optics bundles
  - Nonclassical imaging systems
- Lens aberrations
  - Seidel sums
  - Spherical aberration
  - Coma
  - Astigmatism
  - Petzval curvature
  - Distortion
- Image brightness
  - General relations
  - Distribution of illumination over an image
  - Visual brightness
Optics and information theory
- General observations
  - Temporal frequency response
  - Nonlinear optical systems
- Image formation
  - Impulse response
  - Transfer function
- Partially coherent light
  - Development and examples of the theory
  - The mutual coherence function
- Optical processing
  - Coherent optical systems
  - Filtering
- Holography
  - Theory
  - Applications
    - Image-forming
    - Non-image-forming
    - Optical elements
- Nonlinear optics

References & Edit History Related Topics

Images & Videos

Are invisibility cloaks possible in reality?

Understand how a pinhole focuses light and why lenses are better than pinholes

Two diagrams compare light reflection: the top shows blue incident and reflected rays bouncing off a smooth surface, with equal angles from the normal; the bottom shows rays scattering from a rough surface, with normals and angles marked at various points.

$law of refraction$ $refractive indices and dispersive powers$

Close-up of fiber optic cables with glowing tips fanned out against a dark background, illustrating telecommunications technology.

$refraction$

Gauss theory of lenses

telescopic rifle sight

At a Glance

Close-up of fiber optic cables with glowing tips fanned out against a dark background, illustrating telecommunications technology.

optics: Media

physics

Videos

Are invisibility cloaks possible in reality?

Are invisibility cloaks possible in reality?

Learn about researchers' attempts to create invisibility.

Video: © American Chemical Society (A Britannica Publishing Partner)

Understand how a pinhole focuses light and why lenses are better than pinholes

Understand how a pinhole focuses light and why lenses are better than pinholes

Learn how a pinhole can focus light and about the advantages of lenses over pinholes.

Video: © MinutePhysics (A Britannica Publishing Partner)

Images

Two diagrams compare light reflection: the top shows blue incident and reflected rays bouncing off a smooth surface, with equal angles from the normal; the bottom shows rays scattering from a rough surface, with normals and angles marked at various points.

Reflection of light

In the reflection of light, the angle of incidence is equal to the angle of reflection,...

Encyclopædia Britannica, Inc.

$law of refraction$

law of refraction

Figure 1: The law of refraction. Plane light wave at position AA′ in medium...

Encyclopædia Britannica, Inc.

$refractive indices and dispersive powers$

refractive indices and dispersive powers

Figure 2: Relationships between refractive indices and dispersive powers of several...

Encyclopædia Britannica, Inc.

Close-up of fiber optic cables with glowing tips fanned out against a dark background, illustrating telecommunications technology.

fibre optics

The hair-thin fibres used in fibre optics.

© Kitch Bain/Shutterstock.com

refraction

Figure 3: Graphic refraction procedures (see text).

Encyclopædia Britannica, Inc.

ray tracing

ray tracing

Figure 4: Trigonometrical ray tracing (see text).

Encyclopædia Britannica, Inc.

Gauss theory of lenses

Gauss theory of lenses

Figure 5: The Gauss theory (see text).

Encyclopædia Britannica, Inc.

telescopic rifle sight

telescopic rifle sight

Figure 6: Operating principle of the telescopic rifle sight (see text).

Encyclopædia Britannica, Inc.

Porro prism

Porro prism

Figure 7: Porro prism.

Encyclopædia Britannica, Inc.

optical fibre

optical fibre

Light ray passing through an optical fibre.

Encyclopædia Britannica, Inc.

lens aberrations

lens aberrations

Figure 8: Lens aberrations.

Encyclopædia Britannica, Inc.

Diagram showing how a microscope forms images according to Abbe Theory, with labeled components including condenser, specimen, objective lens, and focal plane, plus insets illustrating constructive and destructive interference and spatial frequency patterns.

image formation in a microscope; Abbe theory

Image formation in a microscope, according to the Abbe theory. Specimens are illuminated...

Encyclopædia Britannica, Inc.

two-lens coherent optical processing system

two-lens coherent optical processing system

Figure 9: Two-lens coherent optical processing system, showing how the raster periodicity...

Encyclopædia Britannica, Inc.

holography

holography

Figure 10: Holography.

Encyclopædia Britannica, Inc.

Optics of the pupil

Optics of the pupil

Encyclopædia Britannica, Inc.

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