Slowing light in an optical cavity with mechanical resonators and
mirrors

Date:
October 16, 2020
Source:
Springer
Summary:
Scientists have demonstrated the theory behind how a cavity
optomechanical system induces OMIT and reduces the speed of light.



FULL STORY ========================================================================== Scientists have demonstrated the theory behind how a cavity optomechanical system induces OMIT and reduces the speed of light. Theoretical physicists Kamran Ullah and Hameed Ullah have shown how a position-dependent mass optomechanical system involving a cavity between two mirrors, one attached
to a resonator, can enhance induced transparency and reduce the speed
of light.


==========================================================================
We are all taught at high school that the speed of light through a vacuum
is about 300000 km/s, which means that a beam from Earth takes about
2.5 seconds to reach the Moon. It naturally moves more slowly through transparent objects, however, and scientists have found ways to slow
it dramatically. Optomechanics, or the interaction of electromagnetic
radiation with mechanical systems, is a relatively new and effective
way of approaching this. Theoretical physicists Kamran Ullah from
Quaid-i-Azam University, Islamabad, Pakistan and Hameed Ullah from the Institute of Physics, Porto Alegre, Brazil have now demonstrated how
light is slowed in a position-based mass optomechanical system. This
work has been published in EPJ D.

Ullah and Ullah describe cavity optomechanics, which involves optical
modes set up in a cavity between mirrors. The cavity mode, which is driven
by a strong field and probed by a weak field, provides a 'playground' for investigating phenomena including slow light and optomechanically induced transparency (OMIT). The latter is a quantum effect in which the optical response of atoms and molecules is controlled by an electromagnetic
field. In this work, the physicists studied a cavity system comprising
a fixed mirror and a movable one.

The moving mirror oscillates along the axis of the cavity with a single harmonic frequency. By considering the total mass of the resonator as
dependent on its position, and calculating the effective Hamiltonian of
the whole system (which describes its total energy), Ullah and Ullah
showed how the system can enhance OMIT and slow light. As the mass
is position-dependent, the system is non-linear and the nature and
magnitude of the quantum effects observed depend strongly on the value
of a non-linear parameter, alpha.

And this work is not entirely abstruse. OMIT and slow light already
have important applications in quantum information processing, optical
switches and optical sensing, and these technologies can only become more useful as quantum computing moves out of the lab into the workaday world.


========================================================================== Story Source: Materials provided by Springer. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Kamran Ullah, Hameed Ullah. Enhanced optomechanically induced
transparency and slow/fast light in a position-dependent mass
optomechanics. The European Physical Journal D, 2020; 74 (10)
DOI: 10.1140/epjd/e2020-10286-1 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201016100922.htm

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