Letter | Published:

Stimulated Optical Radiation in Ruby

Naturevolume 187pages493494 (1960) | Download Citation



Schawlow and Townes1 have proposed a technique for the generation of very monochromatic radiation in the infra-red optical region of the spectrum using an alkali vapour as the active medium. Javan2 and Sanders3 have discussed proposals involving electron-excited gaseous systems. In this laboratory an optical pumping technique has been successfully applied to a fluorescent solid resulting in the attainment of negative temperatures and stimulated optical emission at a wave-length of 6943 Å. ; the active material used was ruby (chromium in corundum).

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  1. 1

    Schawlow, A. L., and Townes, C. H., Phys. Rev., 112, 1940 (1958).

  2. 2

    Javan, A., Phys. Rev. Letters, 3, 87 (1959).

  3. 3

    Sanders, J. H., Phys. Rev. Letters, 3, 86 (1959).

  4. 4

    Maiman, T. H., Phys. Rev. Letters, 4, 564 (1960).

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  1. Hughes Research Laboratories, A Division of Hughes Aircraft Co., Malibu, California

    • T. H. MAIMAN


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