Browse Definitions :
Definition

laser

A laser is a coherent and focused beam of photons; coherent, in this context, means that it is all one wavelength, unlike ordinary light which showers on us in many wavelengths.

The acronym laser stands for "light amplification by stimulated emission of radiation." Lasers work as a result of resonant effects. The output of a laser is a coherent electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the same frequency and phase.

In a basic laser, a chamber called a cavity is designed to internally reflect infrared (IR), visible-light, or ultraviolet (UV) waves so they reinforce each other. The cavity can contain gases, liquids, or solids. The choice of cavity material determines the wavelength of the output. At each end of the cavity, there is a mirror. One mirror is totally reflective, allowing none of the energy to pass through; the other mirror is partially reflective, allowing approximately 5 percent of the energy to pass through. Energy is introduced into the cavity from an external source; this is called pumping.

As a result of pumping, an electromagnetic field appears inside the laser cavity at the natural (resonant) frequency of the atoms of the material that fills the cavity. The waves reflect back and forth between the mirrors. The length of the cavity is such that the reflected and re-reflected wave fronts reinforce each other in phase at the natural frequency of the cavity substance. Electromagnetic waves at this resonant frequency emerge from the end of the cavity having the partially-reflective mirror. The output may appear as a continuous beam, or as a series of brief, intense pulses.

The ruby laser, a simple and common type, has a rod-shaped cavity made of a mixture of solid aluminum oxide and chromium. The output is in pulses that last approximately 500 microseconds each. Pumping is done by means of a helical flash tube wrapped around the rod. The output is in the red visible range.

A blue laser has a shorter wavelength than the red laser, and the ability to store and read two to four times the amount of data.

The helium-neon laser is another popular type, favored by electronics hobbyists because of its moderate cost. As its name implies, it has a cavity filled with helium and neon gases. The output of the device is bright crimson. Other gases can be used instead of helium and neon, producing beams of different wavelengths. Argon produces a laser with blue visible output. A mixture of nitrogen, carbon dioxide, and helium produces IR output.

Lasers are one of the most significant inventions developed during the20th century. They have found a tremendous variety of uses in electronics, computer hardware, medicine, and experimental science.

This was last updated in August 2018

Continue Reading About laser

Networking
  • network management system

    A network management system, or NMS, is an application or set of applications that lets network engineers manage a network's ...

  • host (in computing)

    A host is a computer or other device that communicates with other hosts on a network.

  • Network as a Service (NaaS)

    Network as a service, or NaaS, is a business model for delivering enterprise WAN services virtually on a subscription basis.

Security
  • WebAuthn API

    The Web Authentication API (WebAuthn API) is a credential management application program interface (API) that lets web ...

  • Common Vulnerability Scoring System (CVSS)

    The Common Vulnerability Scoring System (CVSS) is a public framework for rating the severity of security vulnerabilities in ...

  • Dridex malware

    Dridex is a form of malware that targets victims' banking information, with the main goal of stealing online account credentials ...

CIO
  • audit program (audit plan)

    An audit program, also called an audit plan, is an action plan that documents what procedures an auditor will follow to validate ...

  • blockchain decentralization

    Decentralization is the distribution of functions, control and information instead of being centralized in a single entity.

  • outsourcing

    Outsourcing is a business practice in which a company hires a third party to perform tasks, handle operations or provide services...

HRSoftware
  • team collaboration

    Team collaboration is a communication and project management approach that emphasizes teamwork, innovative thinking and equal ...

  • employee self-service (ESS)

    Employee self-service (ESS) is a widely used human resources technology that enables employees to perform many job-related ...

  • learning experience platform (LXP)

    A learning experience platform (LXP) is an AI-driven peer learning experience platform delivered using software as a service (...

Customer Experience
  • market segmentation

    Market segmentation is a marketing strategy that uses well-defined criteria to divide a brand's total addressable market share ...

  • sales pipeline

    A sales pipeline is a visual representation of sales prospects and where they are in the purchasing process.

  • market basket analysis

    Market basket analysis is a data mining technique used by retailers to increase sales by better understanding customer purchasing...

Close