Prospects for broadband spectrum Raman optical refrigeration
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2018-09-14 |
| Authors | Reid Vorbach, C.M. Fortmann, Rachel Tyo, Claire Alvine, Mostafa Sadoqi |
| Citations | 3 |
Abstract
Section titled āAbstractāDescribed are the prospects for broadband optical refrigeration based on Raman scattering of incoherent light. Laser pumped rare earth fluorescence has been demonstrated and commercial applications are sure to follow. Broadband refrigeration requires strong Raman scattering and large Raman shift. Also required are spectral management and photonic patterning to offset the unfavorable anti-Stokeās to Stokeās shift ratio. Materials such as diamond, silicon, and a number of molecular systems are ideal and have low absorption. Optics splits the broadband spectrum into light and dark bands with width corresponding to the Raman shift. Broadband spectrums where photon flux decreases with increasing photon energy are ideal. By tailoring the incoming spectrum, by utilizing extremely transparent strong Raman shift materials and by photonic inhibition of Stokeās shifted light the prospect become feasible. The Raman optical cross- section increases with decreasing particle size (until the particle become too small to support the Raman-phonons). Where conservation of phonon states in these truncated Brillioun-zone particles requires an increased density (number/cm<sup>3</sup>) of the allowed-states to compensate for states lost to particle size. Nonetheless, the anti-Stokes to Stokes ratio is approximately one-to-two at laboratory temperature. Thin film deposited diamond is an excellent candidate for refrigeration applications due to its high transparency small grain size and its large Raman magnitude and large shift. Simple one-dimensional photonic structures selectively inhibit the Stokeās shifted light making refrigeration possible.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal SourceāReferences
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