laser

(noun)

A device that produces a monochromatic, coherent beam of light.

Related Terms

Examples of laser in the following topics:

  • Lasers

    • A laser consists of a gain medium, a mechanism to supply energy to it, and something to provide optical feedback.
    • Having examined stimulated emission and optical amplification process in the "Lasers, Applications of Quantum Mechanics" section, this atom looks at how lasers are built.
    • When a gain medium is placed in an optical cavity, a laser can then produce a coherent beam of photons.
    • There are many types of lasers depending on the gain media and mode of operation .
    • Laser types with distinct laser lines are shown above the wavelength bar, while below are shown lasers that can emit in a wavelength range.

  • Lasers

    • A laser is a device that emits monochromatic light (electromagnetic radiation).
    • The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.
    • Laser is distinct from other light sources for its high degree of spatial and temporal coherence, which means that laser outputs a narrow beam that maintains its temporal-phase relationship.
    • Principles of laser operation are largely based on quantum mechanics.
    • Identify process that generates laser emission and the defining characteristics of laser light

  • Tattoos

    • Pre-laser tattoo removal methods include dermabrasion, salabrasion (scrubbing the skin with salt), cryosurgery, and excision, which is sometimes still used along with skin grafts for larger tattoos.
    • Laser tattoo removal usually refers to the non-invasive removal of tattoo pigments using Q-switched (pulsed) lasers.
    • Multiple factors contribute to the success of laser tattoo removal, one of which is a patient's own immune system.
    • Although laser treatment is currently the gold standard method to remove a tattoo, unwanted side effects of laser tattoo removal include the possibility of discoloration of the skin such as hypo-pigmentation (white spots, more common in darker skin) and hyper-pigmentation (dark spots) as well as textural changes.

  • Using Interference to Read CDs and DVDs

    • Optical discs are digital storing media read in an optical disc drive using laser beam.
    • They are read in an optical disc drive which directs a laser beam at the disc.
    • First, a laser beam is shot at the disc.
    • The data is stored either by a stamping machine or laser and is read when the data is illuminated by a laser diode in the disc drive.

  • Holography

    • It involves the use of a laser, interference, diffraction, light intensity recording and suitable illumination of the recording.
    • A hologram requires a laser as the sole light source.
    • Laser is required as a light source to produce an interference pattern on the recording plate.
    • Holography requires a specific exposure time, which can be controlled using a shutter, or by electronically timing the laser
    • Process: When the two laser beams reach the recording medium, their light waves intersect and interfere with each other.

  • Implications of Quantum Mechanics

    • Examples include the laser , the transistor (and thus the microchip), the electron microscope, and magnetic resonance imaging (MRI).

  • Momentum Transfer and Radiation Pressure Atom

    • There are many variations of laser cooling, but they all use radiation pressure to remove energy from atomic gases (and therefore cool the sample).
    • In laser cooling (sometimes called Doppler cooling), the frequency of light is tuned slightly below an electronic transition in the atom.
    • Thus if one applies light from two opposite directions, the atoms will always scatter more photons from the laser beam pointing opposite to their direction of motion (typical setups applies three opposing pairs of laser beams as in ).
    • Simple laser cooling setups can produce a cold sample of atomic gases at around 1mK (=10-3 K) starting from a room temperature gas.

  • The Noble Gases (Group 18)

    • The noble gases are also used in excimer lasers, which are based on short-lived electronically excited molecules known as excimers.
    • The excimers used for lasers may be noble gas dimers such as Ar2, Kr2, or Xe2, or, more commonly, the noble gas is combined with a halogen in excimers such as ArF, KrF, XeF, or XeCl.
    • These lasers produce ultraviolet light, which, due to its short wavelength (193 nm for ArF and 248 nm for KrF), allows for high-precision imaging.
    • Excimer lasers have many industrial, medical, and scientific applications.
    • They are used for microlithography and microfabrication, which are essential for integrated circuit manufacturing; and for laser surgery, including laser angioplasty and eye surgery.

  • Energy, Mass, and Momentum of Photon

    • They are emitted from light sources such as floor lamps or lasers .

  • Einstein's Postulates

    • Now, instead of a baseball, let's say you have a laser pointer.
    • You turn on the laser pointer while you are on a moving train.
    • What would be the speed of light from the laser pointer for a stationary observer on the ground?