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Optical refrigeration


The idea of cooling a solid-state optical material by simply shining a laser beam onto it may seem counterintuitive, but this is rapidly becoming a promising technology for future cryocoolers. Here, we chart the evolution of the science of optical refrigeration in rare-earth-doped solids and semiconductors from its origins through to the present day.

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Figure 1: An energy diagram showing one way anti-Stokes fluorescence could occur.
Figure 2: Optical cooling performance.
Figure 3: Schematic of an optical refrigeration system.
Figure 4: Semiconductor optical cooling.
Figure 5: The external quantum efficiency.
Figure 6: A vacuum 'nanogap' structure where the heterostructure is situated (for example, supported by posts) at a subwavelength distance from an absorber.


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This work has been supported by the Air Force Office of Scientific Research (MURI program), the National Aeronautics and Space Administration (NASA) and the US Department of Energy. The authors thank M. P. Hasselbeck and D. Seletskiy for reading the manuscript.

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Correspondence to Richard I. Epstein.

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Sheik-Bahae, M., Epstein, R. Optical refrigeration. Nature Photon 1, 693–699 (2007).

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