How is a laser different from other light?

Answer 1

A laser is different in three main ways:

1- The light emitted from a laser is monochromatic, that is, it only has one wavelength (color). Ordinary light on the other hand, is a combination of many different wavelengths (colors).

2- It is coherent, that is, the waves of light of the laser are in phase. Just like two sea waves when they are both at their maximum height, all waves of the light in a laser are exactly at the same amplitude, all time.

3- It is highly directional. Laser light is emitted as a narrow beam in a specific direction. Ordinary light coming from the sun, a light bulb or a candle is emitted in various directions from the source. Since laser rays are so concentrated they also have much more brilliance than rays from other sources.

Answer 2

LASER is an acronym for 'Light Amplification by Stimulatred Emission of Radiation". Laser is produced by stimulated emission hence it has got its name. Lasers differ from ordinary light in following characteristics: Laser light is higly monochromatic while ordinary is not. Laser light has unidirectional nature. Laser is a coherent beam of photons.

Answer 3

Laser light is very different from normal light. Laser light has the following properties:

• The light released is monochromatic. It contains one specific wavelength of light (one specific color). The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit.
• The light released is coherent. It is "organized" -- each photon moves in step with the others. This means that all of the photons have wave fronts that launch in unison.
• The light is very directional. A laser light has a very tight beam and is very strong and concentrated. A flashlight, on the other hand, releases light in many directions, and the light is very weak and diffuse.

To make these three properties occur takes something called stimulated emission. This does not occur in your ordinary flashlight -- in a flashlight, all of the atoms release their photons randomly. In stimulated emission, photon emission is organized.

The photon that any atom releases has a certain wavelength that is dependent on the energy difference between the excited state and the ground state. If this photon (possessing a certain energy and phase) should encounter another atom that has an electron in the same excited state, stimulated emission can occur. The first photon can stimulate or induce atomic emission such that the subsequent emitted photon (from the second atom) vibrates with the same frequency and direction as the incoming photon.

The other key to a laser is a pair of mirrors, one at each end of the lasing medium. Photons, with a very specific wavelength and phase, reflect off the mirrors to travel back and forth through the lasing medium. In the process, they stimulate other electrons to make the downward energy jump and can cause the emission of more photons of the same wavelength and phase. A cascade effect occurs, and soon we have propagated many, many photons of the same wavelength and phase. The mirror at one end of the laser is "half-silvered," meaning it reflects some light and lets some light through. The light that makes it through is the laser light.

Answer 4

Light from an ordinary lamp contains components of different wave lengths like blue, red, etc. and are not amplified or concentrated. Laser has one wavelength and very concentrated.

"A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation. The emitted laser light is notable for its high degree of spatial and temporal coherence, unattainable using other technologies.

Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam." Laser beams can be focused to very tiny spots, achieving a very high irradiance. Or they can be launched into a beam of very low divergence in order to concentrate their power at a large distance."