Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Laser cooling of solids to cryogenic temperatures


Laser radiation has been used to cool matter ranging from dilute gases to micromechanical oscillators. In Doppler cooling of gases, the translational energy of atoms is lowered through interaction with a laser field1,2. Recently, cooling of a high-density gas through collisional redistribution of radiation has been demonstrated3. In laser cooling of solids, heat is removed through the annihilation of lattice vibrations in the process of anti-Stokes fluorescence4,5,6. Since its initial observation in 1995, research7,8,9,10,11,12,13,14,15 has led to achieving a temperature of 208 K in ytterbium-doped glass16. In this Letter, we report laser cooling of ytterbium-doped LiYF4 crystal to a temperature of 155 K starting from ambient, with a cooling power of 90 mW. This is achieved by making use of the Stark manifold resonance in a crystalline host, and demonstrates the lowest temperature achieved to date without the use of cryogens or mechanical refrigeration. Optical refrigeration has entered the cryogenic regime, surpassing the performance of multi-stage Peltier coolers.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Optical absorption, emission and cooling efficiency spectra of 5% doped Yb3+ ion in a YLF crystal.
Figure 2: Experimental arrangement and cooling data for Yb:YLF.
Figure 3: Parametric representation of the cooling efficiency in 5% doped Yb:YLF crystal.


  1. 1

    Hänsch, T. W. & Schawlow, A. L. Cooling of gases by laser radiation. Opt. Commun. 13, 68–69 (1975).

    ADS  Article  Google Scholar 

  2. 2

    Chu, S., Cohen-Tannoudji, C. & Philips, W. D. For development of methods to cool and trap atoms with laser light. Nobel Prize in Physics (1997).

  3. 3

    Vogl, U. & Weitz, M. Laser cooling by collisional redistribution of radiation. Nature 461, 70–74 (2009).

    ADS  Article  Google Scholar 

  4. 4

    Pringsheim, P. Zwei bemerkungen über den unterschied von lumineszenz- und temperaturstrahlung. Z. Phys. 57, 739–746 (1929).

    ADS  Article  Google Scholar 

  5. 5

    Epstein, R. I., Buchwald, M., Edwards, B., Gosnell, T. & Mungan, C. Observation of laser induced fluorescent cooling of a solid. Nature 377, 500–503 (1995).

    ADS  Article  Google Scholar 

  6. 6

    Sheik-Bahae, M. & Epstein, R. I. Optical refrigeration. Nature Photon. 12, 693–699 (2007).

    ADS  Article  Google Scholar 

  7. 7

    Mungan, C. E., Buchwald, M. I., Edwards, B. C., Epstein, R. I. & Gosnell, T. R. Laser cooling of a solid by 16 K starting from room temperature. Phys. Rev. Lett. 78, 1030–1033 (1997).

    ADS  Article  Google Scholar 

  8. 8

    Bowman, S. R. & Mungan, C. E. New materials for optical cooling. Appl. Phys. B 71, 807–811 (2000).

    ADS  Article  Google Scholar 

  9. 9

    Hoyt, C. W., Sheik-Bahae, M., Epstein, R. I., Edwards, B. C. & Anderson, J. E. Observation of anti-Stokes fluorescent cooling in thulium-doped glass. Phys. Rev. Lett. 85, 3600–3603 (2000).

    ADS  Article  Google Scholar 

  10. 10

    Mendioroz, A. et al. Anti-Stokes laser cooling in Yb3+-doped KPb2Cl5 crystal. Opt. Lett. 27, 1525–1527 (2002).

    ADS  Article  Google Scholar 

  11. 11

    Fernandez, J., Garcia-Adeva, A. J. & Balda, R. Anti-Stokes laser cooling in bulk erbium-doped materials. Phys. Rev. Lett. 97, 033001 (2006).

    ADS  Article  Google Scholar 

  12. 12

    Bigotta, S. et al. Spectroscopic and laser cooling results on Yb3+-doped BaY2F8 single crystal. J. Appl. Phys. 100, 013109 (2006).

    ADS  Article  Google Scholar 

  13. 13

    Bigotta, S. et al. Laser cooling of solids: new results with single fluoride crystals. Nuovo Cimento B Serie 122, 685694 (2007).

    Google Scholar 

  14. 14

    Patterson, W. et al. Anti-Stokes luminescence cooling of Tm3+ doped BaY2F8 . Opt. Express 16, 1704–1710 (2008).

    ADS  Article  Google Scholar 

  15. 15

    Condon, N. J., Bowman, S. R., O'Connor, S. P., Quimby, R. S. & Mungan, C. E. Optical cooling in Er3+:KPb2Cl5 . Opt. Express 17, 5466–5472 (2009).

    ADS  Article  Google Scholar 

  16. 16

    Thiede, J., Distel, J., Greenfield, S. R. & Epstein, R. I. Cooling to 208 K by optical refrigeration. Appl. Phys. Lett. 86, 154107 (2005).

    ADS  Article  Google Scholar 

  17. 17

    Epstein, R. I. & Sheik-Bahae, M. Optical Refrigeration (Wiley-VCH, 2009).

    Google Scholar 

  18. 18

    Gauck, H., Gfroerer, T. H., Renn, M. J., Cornell, E. A. & Bertness, K. A. External radiative quantum efficiency of 96% from a GaAs/GaInP heterostructure. Appl. Phys. A 64, 143–147 (1997).

    ADS  Article  Google Scholar 

  19. 19

    Sheik-Bahae, M. & Epstein, R. I. Can laser light cool semiconductors? Phys. Rev. Lett. 92, 247403 (2004).

    ADS  Article  Google Scholar 

  20. 20

    Finkeissen, E., Potemski, M., Wyder, P., Vina, L. & Weimann, G. Cooling of a semiconductor by luminescence up-conversion. Appl. Phys. Lett. 75, 1258–1260 (1999).

    ADS  Article  Google Scholar 

  21. 21

    Höhberger-Metzger, C. & Karrai, K. Cavity cooling of a microlever. Nature 432, 1002–1005 (2004).

    ADS  Article  Google Scholar 

  22. 22

    Hehlen, M. P., Epstein, R. I. & Inoue, H. Model of laser cooling in the Yb3+-doped fluorozirconate glass ZBLAN. Phys. Rev. B 75, 144302 (2007).

    ADS  Article  Google Scholar 

  23. 23

    Sheik-Bahae, M. & Epstein, R. I. Laser cooling of solids. Laser Photon. Rev. 3, 67–84 (2009).

    ADS  Article  Google Scholar 

  24. 24

    Coluccelli, N. et al. Diode pumped passively mode-locked Yb:YLF laser. Opt. Express 16, 2922–2927 (2008).

    ADS  Article  Google Scholar 

  25. 25

    Seletskiy, D. V. et al. Cooling of Yb:YLF using cavity enhanced resonant absorption. Proc. SPIE 6907, 6907B (2008).

    Google Scholar 

  26. 26

    Sugiyama, A., Katsurayama, M., Anzai, Y. & Tsuboi, T. Spectroscopic properties of Yb doped YLF grown by a vertical Bridgman method. J. Alloy Compound 408–412, 780–783 (2006).

    Article  Google Scholar 

  27. 27

    Hoyt, C. W. et al. Advances in laser cooling of thulium-doped glass. J. Opt. Soc. Am. B 20, 1066–1074 (2003).

    ADS  Article  Google Scholar 

  28. 28

    Imangholi, B. et al. Differential luminescence thermometry in semiconductor laser cooling. Proc. SPIE 6115, 61151C (2006).

    Article  Google Scholar 

  29. 29

    McCumber, D. E. Einstein relations connecting broadband emission and absorption spectra. Phys. Rev. 136, A954–A957 (1964).

    ADS  Article  Google Scholar 

  30. 30

    Mills, G. & Mord, A. Performance modeling of optical refrigerators. Cryogenics 46, 176–182 (2005).

    ADS  Article  Google Scholar 

Download references


This work has been supported by the Air Force Office of Scientific Research (MURI program), grant FA 9550-04-1-0356. The authors thank M.P. Hasselbeck and R.I. Epstein for helpful discussions and M.P. Hasselbeck for proofreading the manuscript. The authors would also like to acknowledge the skill and competence of I. Grassini in preparing the sample.

Author information




D.V.S. and M.S.B. designed and implemented the experiments. D.V.S. and S.D.M. performed the experiments, designed radiation shielding and carried out calibrations. S.B., A.D.L. and M.T. grew and prepared the high-purity Yb:YLF crystals and provided supporting spectroscopic data. All authors contributed to the final manuscript.

Corresponding author

Correspondence to Mansoor Sheik-Bahae.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Seletskiy, D., Melgaard, S., Bigotta, S. et al. Laser cooling of solids to cryogenic temperatures. Nature Photon 4, 161–164 (2010).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing