Related topics: light · laser · electrons · molecules · atoms

Bright colors produced by laser heating

Most of the colors on today's paper and fabric are made using dyes or pigments. But colors can also be produced by modifying a material's surface at the nanoscale, causing the surface to reflect or scatter different frequencies ...

Quantum dot ring lasers emit colored light

Researchers have designed a new type of laser called a quantum dot ring laser that emits red, orange, and green light. The different colors are emitted from different parts of the quantum dot—red from the core, green from ...

Accelerating light beams in curved space

By shining a laser along the inside shell of an incandescent light bulb, physicists have performed the first experimental demonstration of an accelerating light beam in curved space. Rather than moving along a geodesic trajectory ...

Optical metacage blocks light from entering or escaping

(Phys.org)—Physicists have built a nanowire cage that blocks one or more wavelengths of light from either entering or escaping, yet allows liquids and gases to pass through the small gaps between the nanowires. The "optical ...

Levitating objects with light

Researchers at Caltech have designed a way to levitate and propel objects using only light, by creating specific nanoscale patterning on the objects' surfaces.

New shapes of laser beam 'sneak' through opaque media

Researchers have found a way to pre-treat a laser beam so that it enters opaque surfaces without dispersing—like a headlight that's able to cut through heavy fog at full strength.

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Laser

A laser is a device that emits light (electromagnetic radiation) through a process called stimulated emission. The term laser is an acronym for light amplification by stimulated emission of radiation. Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses. Typically, lasers are thought of as emitting light with a narrow wavelength spectrum ("monochromatic" light). This is not true of all lasers, however: some emit light with a broad spectrum, while others emit light at multiple distinct wavelengths simultaneously. The coherence of typical laser emission is distinctive. Most other light sources emit incoherent light, which has a phase that varies randomly with time and position.

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