Hidden Laser Communications Through Matter -An application of meV-scale hidden photons-

Abstract

Currently, there are a number of light-shining-through-walls experiments searching for hidden photons -- light, sub-eV-scale, abelian gauge bosons beyond the standard model which mix kinetically with the standard photon. We show that in the case that one of these experiments finds evidence for hidden photons, laser communications through matter, using methods from free-space optics, can be realized in the very near future, with a channel capacity of more than 1 bit per second, for a distance up to the Earth's diamater.

Figures (2)

• Figure 1: Isocontours of channel capacity (bit/s) for our hidden photon communication system across the Earth's diameter. >From bottom to top the channel capacities are $1,10,100,500,1000$ bit/s. The dashed (solid) lines correspond to setups with (without) phase shift plates. Further details are given in the main text. The dot and triangle are our benchmark points $(m_{\gamma^{\prime}}^\bullet,\chi^\bullet)$ and $(m_{\gamma^{\prime}}^\blacktriangle,\chi^\blacktriangle)$. Also shown are current experimental limits on the possible existence of a hidden photon of mass $m_{\gamma^\prime}$, mixing kinetically with the photon, with a mixing parameter $\chi$. Strong constraints arise from the non-observation of deviations from the Coulomb law (yellow) Williams:1971msBartlett:1988yy, from Cosmic Microwave Background (CMB) measurements of the effective number of neutrinos and the blackbody nature of the spectrum (black) Jaeckel:2008fi, from light-shining-through-walls (LSW) experiments (grey) Ruoso:1992nxCameron:1993mrRobilliard:2007bqAhlers:2007rdChou:2007zzcAhlers:2007qfAfanasev:2008jtFouche:2008jkAfanasev:2008fv, and from searches of solar hidden photons with the CAST experiment (purple) Andriamonje:2007ewRedondo:2008aa. The white region in parameter space is currently unexplored, but may be accessed by experiments in the very near future, in particular by improvements in LSW experiments (for proposed experiments probing this region, see Refs. Jaeckel:2007chGninenko:2008pzJaeckel:2008sz).
• Figure 2: Sketch of the HP communication system. A laser modulated in amplitude or polarization feeds a resonant cavity placed inside a vacuum tube. A fraction of the power inside the cavity oscillates into hidden photons that being weakly interacting scape the cavity and can traverse dense media without loosing information. The receiver is another cavity in vacuum locked to the frequency of the HP signal. HPs resonantly reconvert into photons that are finally detected at both the receiver cavity ends.