Accession Number : ADA293930

Title :   Optical Frequency Standards: Hertz-Level Working Standards and their Absolute Frequency Measurement.

Descriptive Note : Final rept.,

Corporate Author : COLORADO UNIV AT BOULDER

Personal Author(s) : Hollberg, Leo ; Hall, John

PDF Url : ADA293930

Report Date : 26 AUG 1994

Pagination or Media Count : 6

Abstract : Promising optical frequency/wavelength standards in the visible based on neutral atoms and precise laser sources are studied. In particular we have developed high accuracy systems using diode-lasers with calcium atoms and also diode-pumped Yag-lasers with Iodine molecules. An actual frequency measurement of the Iodine transition at 532 nm is made with the frequency doubled Yag system. On the calcium transition at 657 nm in the red, optical Ramsey-fringes as narrow as 10 kHz have been observed with a high signal-to-noise ratio using diode lasers. High resolution multi-photon spectroscopy on laser cooled and trapped atoms (Na and Cs) have also been explored. In these pursuits, significant new diode-laser and frequency- measurement technology has been developed, including; highly stabilized diode and Yag lasers, the ability to coherently measure the frequency difference between two lasers to as high as approx. 700GHz, and the extension of the spectral coverage of diode laser sources to the blue (for laser cooling of calcium) and IR spectral regions by using nonlinear optical techniques. jg

Descriptors :   *OPTICAL PROPERTIES, *FREQUENCY STANDARDS, STABILIZATION, DIODES, YTTRIUM ALUMINUM GARNET, YAG LASERS, SOURCES, CALCIUM, MEASUREMENT, MOLECULES, NEUTRAL, SIGNAL TO NOISE RATIO, COHERENCE, SODIUM, SEMICONDUCTOR LASERS, TRAPPING(CHARGED PARTICLES), SEMICONDUCTOR DIODES, ATOMS, NONLINEAR OPTICS, LASERS, COOLING, CESIUM, HIGH RESOLUTION, PRECISION, IODINE, PHOTONS, INFRARED SPECTRA.

Subject Categories : Optics
      Inorganic Chemistry
      Physical Chemistry
      Lasers and Masers
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE