Applied research and engineering in time and frequency related areas. Emphasis has been on atomic standards, especially rubidium clocks (including product and manufacturing process development).
Basic research in the areas of atomic and molecular physics with emphasis on experimental molecular beam spectroscopy, laser spectroscopy of atomic beams and optical pumping, including initiation and supervision of such research.
Areas of Expertise (7)
Molecular Beam Spectroscopy
Lafayette College: B.S., Physics 1960
University of Michigan: M.S., Physics 1964
University of Michigan: Ph.D., Physics 1966
Harvard University: Postdoctoral Fellow 1968
Evanescent-field interrogator for atomic frequency standards
A novel atomic frequency standard includes an absorption cell containing a first volume of atoms for varying an intensity of light energy passing therethrough; at least one dielectric resonator for generating an evanescent electromagnetic field that effects hyperfine energy level transitions of the first volume of atoms; a waveguide for housing the absorption cell and one or more dielectric resonator(s); a photo detector mounted near an end of the waveguide for receiving light energy; and an electromagnetic energy injector for electromagnetically exciting the dielectric resonator(s). Preferably, a filter cell is positioned adjacent to a dielectric resonator between the absorption cell and the light source. Tuning of the resonant frequency of the dielectric resonator(s) can be accomplished by adjusting the distance between the filter cell and the adjacent dielectric resonator, and can also be accomplished by positioning a dielectric tuning disk adjacent a dielectric resonator, and adjusting the distance between the dielectric resonator and the dielectric tuning disk.
Light stabilization for an optically excitable atomic medium
In an apparatus using optically excited atomic media, such as an atomic frequency standard, a source providing a controlled emission of light for exciting the D1 and/or D2 resonance lines of an alkali gas, such as rubidium or cesium, is controlled by an output generated by digital electronics from the light intensity signal of a light sensor for light transmitted by the alkali gas, an output for representing ambient temperature, and a light intensity-ambient temperature algorithm to substantially eliminate changes in light intensity due to light source aging for the purpose of reducing changes in temperature sensitivity of the apparatus as a function of time and the light-shift contribution to the frequency aging of the standard.
Method and apparatus for reduction of atomic frequency standard phase noise
A method of reducing the interrogation signal phase noise in passive, compact, low-cost commercial atomic standards, particularly phase noise occurring at a Fourier frequency equal to twice the modulation frequency, 2fmod. The method involves selecting the modulation frequency so that 2fmod is on the order of, or greater than, the atomic bandwidth (full width at half maximum signal value).
Method and apparatus for reduction of light intensity decay in optical pumping devices
Optical pumping devices use light reflected from reflecting surfaces to provide a portion of the light incident on the photodetector. Conventional optical pumping devices experience a decay, over time, of the initial light intensity incident on the photodetector. The optical pumping device of the invention experiences reduced light intensity decay. The invention passivates the reflecting surfaces to eliminate tarnish and oxidation by pretarnishing the surfaces or covering the surfaces with a material whose reflectivity does not vary over time, such as gold.