1
Laser Cooling - Sixty Symbols
Laser Cooling - Sixty Symbols
DATE: 2010/08/23::
2
Lesson23: Laser Cooling!
Lesson23: Laser Cooling!
DATE: 2013/03/14::
3
Basics of Laser Cooling
Basics of Laser Cooling
DATE: 2014/09/02::
4
Bose-Einstein Condensate - Coldest Place in the Universe
Bose-Einstein Condensate - Coldest Place in the Universe
DATE: 2013/11/17::
5
Using Laser Cooling to Mark Time
Using Laser Cooling to Mark Time
DATE: 2011/05/20::
6
Laser Cooling (extra footage)
Laser Cooling (extra footage)
DATE: 2010/08/24::
7
homemade diy laser cooling systems
homemade diy laser cooling systems
DATE: 2010/04/06::
8
Absolute Zero- Nobel Prize
Absolute Zero- Nobel Prize
DATE: 2010/02/28::
9
Laser Cooling (Quiz)
Laser Cooling (Quiz)
DATE: 2012/08/13::
10
Laser Cooling Demonstration
Laser Cooling Demonstration
DATE: 2013/04/17::
11
Laser Cooling - From Atomic Clocks to Watching Biomolecules with Steven Chu
Laser Cooling - From Atomic Clocks to Watching Biomolecules with Steven Chu
DATE: 2008/01/10::
12
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Carl Wieman
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Carl Wieman
DATE: 2008/10/03::
13
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Steve Chu
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Steve Chu
DATE: 2008/10/02::
14
Laser Cooling
Laser Cooling
DATE: 2012/06/17::
15
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Carlos Bustamante
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Carlos Bustamante
DATE: 2008/10/03::
16
YTP: William Phillips talks about laser cooling
YTP: William Phillips talks about laser cooling
DATE: 2012/11/04::
17
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Paul Alivisatos
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Paul Alivisatos
DATE: 2008/10/02::
18
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Dave Weiss
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Dave Weiss
DATE: 2008/10/03::
19
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Taekjip Ha and Xiaowei Zhuang
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Taekjip Ha and Xiaowei Zhuang
DATE: 2008/10/03::
20
Lia Ying Li talks about laser cooling and quantum physics
Lia Ying Li talks about laser cooling and quantum physics
DATE: 2014/11/09::
21
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Steve Quake
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Steve Quake
DATE: 2008/10/03::
22
Physics 111: Atom Trapping (MOT)
Physics 111: Atom Trapping (MOT)
DATE: 2012/03/07::
23
Laser Cooling - From Atomic Clocks to Watching Biomolecules with Steven Chu
Laser Cooling - From Atomic Clocks to Watching Biomolecules with Steven Chu
DATE: 2014/07/27::
24
David DeMille , "Laser cooling and slowing of diatomic molecule"
David DeMille , "Laser cooling and slowing of diatomic molecule"
DATE: 2012/06/19::
25
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Wolfgang Ketterle
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Wolfgang Ketterle
DATE: 2008/10/03::
26
trailer laser cooling
trailer laser cooling
DATE: 2015/03/04::
27
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Mark Kasevich
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Mark Kasevich
DATE: 2008/10/03::
28
Laser cooling flow sensor
Laser cooling flow sensor
DATE: 2009/10/10::
29
Eric Hudson, "Sympathetic cooling of molecules with laser-cooled atoms"
Eric Hudson, "Sympathetic cooling of molecules with laser-cooled atoms"
DATE: 2013/10/17::
30
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Vladan Vuletic and Cheng Chin
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Vladan Vuletic and Cheng Chin
DATE: 2008/10/02::
31
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Leo Hollberg and Allen Mills
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Leo Hollberg and Allen Mills
DATE: 2008/10/03::
32
Laser cooling Meaning
Laser cooling Meaning
DATE: 2015/04/24::
33
Affordable Laser Water Chiller Cooler for Hobby Laser like China DCK40III
Affordable Laser Water Chiller Cooler for Hobby Laser like China DCK40III
DATE: 2013/08/15::
34
Brian Odom, "Sympathetic cooling of molecules with laser-cooled atoms"
Brian Odom, "Sympathetic cooling of molecules with laser-cooled atoms"
DATE: 2013/10/17::
35
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Kurt Gibble
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Kurt Gibble
DATE: 2008/10/03::
36
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Jay Keasling
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Jay Keasling
DATE: 2008/10/02::
37
University of Electro-Communications Tokyo, Japan: Optimal Optical Science
University of Electro-Communications Tokyo, Japan: Optimal Optical Science
DATE: 2015/02/27::
38
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Eric Cornell
Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science: Eric Cornell
DATE: 2008/10/03::
39
PDF DOWNLOAD Laser Cooling of Solids
PDF DOWNLOAD Laser Cooling of Solids
DATE: 2015/06/25::
40
DOWNLOAD PDF Optical Refrigeration Science and Applications of Laser Cooling of Solids
DOWNLOAD PDF Optical Refrigeration Science and Applications of Laser Cooling of Solids
DATE: 2015/06/23::
41
How Doppler Cooling Works
How Doppler Cooling Works
DATE: 2012/07/10::
42
Water Cooling Mayhems Uv Laser Green
Water Cooling Mayhems Uv Laser Green
DATE: 2014/09/15::
43
Laser Cutter 2.0 : Active Cooling System
Laser Cutter 2.0 : Active Cooling System
DATE: 2011/09/10::
44
Current progress in laser cooling of antihydrogen
Current progress in laser cooling of antihydrogen
DATE: 2014/10/04::
45
Depilight 808 Diode Laser & Cooling System
Depilight 808 Diode Laser & Cooling System
DATE: 2012/03/08::
46
Cycle time reduction! - Conformal Cooling Tool Insert (SLM - Selective Laser Melting)
Cycle time reduction! - Conformal Cooling Tool Insert (SLM - Selective Laser Melting)
DATE: 2011/10/12::
47
532nm 200mw Green dpss laser with power supply and cooling fan--CivilLaser
532nm 200mw Green dpss laser with power supply and cooling fan--CivilLaser
DATE: 2014/08/22::
48
200mw 405nm Blue Violet Laser module Dot with cooling fan DC 12V -- CivilLaser
200mw 405nm Blue Violet Laser module Dot with cooling fan DC 12V -- CivilLaser
DATE: 2014/08/28::
49
High power 650nm DVD burner laser diode in dry ice cooling with Aixiz Module
High power 650nm DVD burner laser diode in dry ice cooling with Aixiz Module
DATE: 2014/02/02::
50
80mm water cooling radiator for computer Chip CPU GPU VGA RAM Laser cooling cooler Aluminum Heat
80mm water cooling radiator for computer Chip CPU GPU VGA RAM Laser cooling cooler Aluminum Heat
DATE: 2015/07/01::
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RESULTS [51 .. 101]
From Wikipedia, the free encyclopedia
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Laser cooling refers to a number of techniques in which atomic and molecular samples are cooled down to near absolute zero through the interaction with one or more laser fields. All laser cooling techniques rely on the fact that when an object (usually an atom) absorbs and re-emits a photon (a particle of light) its momentum changes. The temperature of an ensemble of particles is larger for larger variance in the velocity distribution of the particles. Laser cooling techniques combine atomic spectroscopy with the aforementioned mechanical effect of light to compress the velocity distribution of an ensemble of particles, thereby cooling the particles.

Simplified principle of Doppler laser cooling:
1 A stationary atom sees the laser neither red- nor blue-shifted and does not absorb the photon.
2 An atom moving away from the laser sees it red-shifted and does not absorb the photon.
3.1 An atom moving towards the laser sees it blue-shifted and absorbs the photon, slowing the atom.
3.2 The photon excites the atom, moving an electron to a higher quantum state.
3.3 The atom re-emits a photon. As its direction is random, there is no net change in momentum over many absorption-emission cycles.

The first example of laser cooling, and also still the most common method (so much so that it is still often referred to simply as 'laser cooling') is Doppler cooling. Other methods of laser cooling include:

Doppler cooling[edit]

Main article: Doppler cooling
The lasers needed for the magneto-optical trapping of rubidium 85: (a) & (b) show the absorption (red detuned to the dotted line) and spontaneous emission cycle, (c) & (d) are forbidden transitions, (e) shows that if a the cooling laser excites an atom to the F=3 state, it is allowed to decay to the "dark" lower hyperfine, F=2 state, which would stop the cooling process, if it were not for the repumper laser (f).

Doppler cooling, which is usually accompanied by a magnetic trapping force to give a magneto-optical trap, is by far the most common method of laser cooling. It is used to cool low density gases down to the Doppler cooling limit, which for Rubidium 85 is around 150 microkelvin.

In Doppler cooling, the frequency of light is tuned slightly below an electronic transition in the atom. Because the light is detuned to the "red" (i.e., at lower frequency) of the transition, the atoms will absorb more photons if they move towards the light source, due to the Doppler effect. 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. In each scattering event the atom loses a momentum equal to the momentum of the photon. If the atom, which is now in the excited state, then emits a photon spontaneously, it will be kicked by the same amount of momentum, but in a random direction. Since the initial momentum loss was opposite to the direction of motion, while the subsequent momentum gain was in a random direction, the overall result of the absorption and emission process is to reduce the speed of the atom (provided its initial speed was larger than the recoil speed from scattering a single photon). If the absorption and emission are repeated many times, the average speed, and therefore the kinetic energy of the atom will be reduced. Since the temperature of a group of atoms is a measure of the average random internal kinetic energy, this is equivalent to cooling the atoms.

Uses[edit]

Laser cooling is primarily used to create ultracold atoms for experiments in quantum physics. These experiments are performed near absolute zero where unique quantum effects such as Bose-Einstein condensation can be observed. Laser cooling has primarily been used on atoms, but recent progress has been made toward laser cooling more complex systems. In 2010, a team at Yale successfully laser-cooled a diatomic molecule.[4] In 2007, an MIT team successfully laser-cooled a macro-scale (1 gram) object to 0.8 K.[5] In 2011, a team from the California Institute of Technology and the University of Vienna became the first to laser-cool a (10 μm x 1 μm) mechanical object to its quantum ground state.[6]

See also[edit]

References[edit]

  1. ^ Laser cooling and trapping of neutral atoms Nobel Lecture by William D. Phillips, Dec 8, 1997. doi:10.1103/RevModPhys.70.721
  2. ^ A. Aspect, E. Arimondo, R. Kaiser, N. Vansteenkiste, and C. Cohen-Tannoudji (1988). "Laser Cooling below the One-Photon Recoil Energy by Velocity-Selective Coherent Population Trapping". Phys. Rev. Lett. 61: 826. doi:10.1103/PhysRevLett.61.826. 
  3. ^ Peter Horak, Gerald Hechenblaikner, Klaus M. Gheri, Herwig Stecher, and Helmut Ritsch (1988). "Cavity-Induced Atom Cooling in the Strong Coupling Regime". Phys. Rev. Lett. 79: 4974. doi:10.1103/PhysRevLett.79.4974. 
  4. ^ E. S. Shuman, J. F. Barry, and D. DeMille (2010). "Laser cooling of a diatomic molecule". Science 467: 820–823. doi:10.1038/nature09443. 
  5. ^ Massachusetts Institute of Technology (2007, April 8). Laser-cooling Brings Large Object Near Absolute Zero. ScienceDaily. Retrieved January 14, 2011.
  6. ^ Caltech Team Uses Laser Light to Cool Object to Quantum Ground State. Caltech.edu. Retrieved June 27, 2013. Updated 10/05/2011

Additional Sources[edit]

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