optikk

Optics, in Norwegian usage optikk, is the branch of physics that studies light: its generation, propagation, interaction with matter, and detection by the eye or sensors. The field covers phenomena from everyday vision to highly engineered devices and includes geometric optics, which treats light as rays, and physical optics, which accounts for wave effects. Modern optics extends across the electromagnetic spectrum, from radio waves to X-rays.

Light can be described as electromagnetic radiation traveling with a characteristic speed c in vacuum. Key concepts include refractive index, reflection, refraction, dispersion, diffraction, interference, and polarization. The behavior of light is governed by laws such as Snell's law, Fermat's principle, and, at a deeper level, Maxwell's equations in electromagnetism.

Geometric optics deals with image formation by lenses and mirrors and underpins devices like cameras, telescopes, and microscopes. Physical optics addresses interference and diffraction and explains phenomena such as thin-film interference and diffraction gratings. Quantum optics, nonlinear optics, and fiber optics study light's particle-like aspects, strong-field interactions, and guided light in fibers. Applications include lasers, optical communications, medical imaging (endoscopy and optical coherence tomography), spectroscopy, and photography.

Historically, optics traces back to ancient and medieval scholars. Ibn al-Haytham wrote influential work on optical experiments and the scientific method. In the 17th century, Newton proposed a corpuscular theory of light while Huygens and Young argued for wave behavior. In the 19th century, James Clerk Maxwell formulated a unified theory of electromagnetism, and later quantum theory refined understanding of light as photons.

Optics is foundational for modern technology and science, enabling imaging, communications, sensing, and fundamental research into light–matter interactions and quantum phenomena.