Celebrating 50 years of LASER
A phonon laser has been demonstrated by optical pumping of a trapped ion. The optomechanical interaction associated with the scattering force gives rise to a Van der Pol dynamical system in which amplification is provided by stimulated emission of centre-of-mass phonons. Steady-state operation occurs by saturation of the mechanical amplification, and excellent agreement is obtained between theory and observed mechanical motion versus pumping. The ability to locate microscopic sources of vibrational coherence that are optically driven and cooled (and addressable using wavelength) might provide a new tool in the field of trapped-ion physics. The fact that phonon laser action is sustained by very low power levels suggests that the ion might be used as an ultra-sensitive force probe. Moreover, amplification of the centre-of-mass motion36 is potentially useful in its own right. The single ion, as a class of phonon laser, represents a kind of zerodimensional limit in which there is no vibronic output coupling. In a Fabry Perot laser analogy, the mirrors would be 100% reflecting and threshold would be determined by internal cavity losses. At the same time, however, this does not preclude other types of useful coupling to the ion's vibrational motion (such as electromagnetic). For example, successful injection locking of the ion phonon laser, in analogy to slaving of a laser oscillator by an external master oscillator, has been achieved recently and will be reported elsewhere.
More details at:
http://www.nature.com/nphys/journal/v5/n9/full/nphys1367.html
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5 comments:
Its definitely revolutionary idea and a concept which would give rise to a different branch in Physics. In order to create Phonon Laser, the idea of making the phonon oscillate would have struck many scientists but the route undertaken in this Nature Physics article is without doubt, one of the most novel ideas I've ever come across.
Yes Rajesh I do remember some part of the conversation we had when we were discussing lasers in college. And I vaguely remember discussing something we had kind of figured out or understood clearly ... help me recall it.
@Utpal
In that discussion:
The last point about making a laser was that,
"anyhow generate a photon. and then it can be amplified to make a laser. In FEL, the photon, which can be amplified, was generated by accelerating electron in a magnetic field"
@Rajesh: 'Somehow generate a photon and the it can be amplified.' See we did have an insight. :)
Also I remember this was outcome of a a series of discussion I had with you over a period of 2-3 day. This exemplifies my believe that discussion is a vital element in learning, understanding and discovery. And one of the reason among others that made me initiate this blog. I hope we are able to make the most of it.
Utpal,
You are right! we reached to this thumb-rule in a few days. I also agree discussion is one of the best ways to understand a subject in a better way. And this was the reason, we still remember this phrase "Somehow generate a photon and then it can be amplified"
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