Light will build-up inside of an optical cavity at specific resonant frequencies, similar to how a held-down guitar string only vibrates to produce specific tones. Positioning a mechanical resonator inside the cavity changes the resonance frequency for light passing through, much as sliding one's fingers up and down a guitar string changes its vibrational tones. Meanwhile, as light passes through the optical cavity, it acts like a tiny tractor beam, pushing and pulling on the mechanical resonator. If an optical cavity is of ultrahigh quality and the mechanical resonator element within is atomic-sized and chilled to nearly absolute zero, the resulting cavity optomechanical system can be used to detect even the slightest mechanical motion. Likewise, even the tiniest fluctuations in the light/vacuum can cause the atoms to wiggle. Changes to the light can provide control over that atomic motion. This not only opens the door to fundamental studies of quantum mechanics that could tell us more about the "classical" world we humans inhabit, but also to quantum information processing, ultrasensitive force sensors, and other technologies that might seem like science fiction today. "There have been proposals to use optomechanical devices as transducers, for example coupling motion to both microwaves and optical frequency light, where one could convert photons from one frequency range to the other," Brooks says. "There have also been proposals for slowing or storing light in the mechanical degrees of freedom, the equivalent of electromagnetically induced transparency or EIT, where a photon is stored within the internal degrees of freedom." http://nanopatentsandinnovations.blogspot.com/2012/08/tractor-beam-works-in-lab-on.html Could an array of transducers be put into a satellite at a Lagrange point to alter the photons that are coming to Earth so that they could regulate their intensity or heat they are producing? Cool thing about the tractor bean technology they have developed with this .
