Optics

Optics is the branch of physics that studies how light behaves and how it interacts with matter — from reflection off a mirror to diffraction through a tiny slit.

Light waves

Light can be described as an electromagnetic wave. Its wavelength determines the color we perceive, and its frequency is closely tied to the energy it carries.

Reflection, refraction & lenses

When light hits a boundary between two media, it's reflected or refracted depending on the angle of incidence. Lenses use refraction deliberately, focusing or spreading light rays — the basic principle behind microscopes, telescopes, and eyeglasses.

Interference & diffraction

When multiple light waves overlap, they can reinforce or cancel each other out. This interplay is central to many measurement techniques and shows up especially when light passes small obstacles or openings.

Polarization & spectroscopy

Restricting a light wave's oscillation to a single plane is called polarization — used, for example, in sunglasses and displays. Spectroscopic analysis of light absorbed or emitted by a material, meanwhile, reveals a great deal about its chemical composition.

Lasers

A laser produces coherent light: all waves oscillate in the same direction and at the same wavelength. That property makes lasers a versatile tool, from medical technology to optical communications.