Stanford Research Institute

Sri International

Robert M Hill

Thomas F Gallagher

Michael V McCusker

Donald C Lorents

Stephen A Edelstein

Davis L Huestis

Halogen transfer laser method and means are disclosed employing a dilute mixture of molecular halogen vapor in high pressure noble gas. Noble gas atoms and molecules are excited by use of electrons to high energy metastable and/or excimer states. Collisional and/or radiative transfer of electronic excitation from the excited noble gas atoms and molecules to the lasing halogen molecules takes place for excitation of halogen molecules to upper ionic states in sufficient number to establish a population inversion in the electronic energy levels thereof for lasing. In addition to halogens, halogen-bearing compounds which dissociate and appropriately recombine to provide diatomic halogen for lasing also may be used. The laser is tunable over an electromagnetic energy range which includes ultraviolet radiation. Operation at high peak power levels with high efficiency is possible.

Noble gas-halogen transfer laser method and means

Isotope separation method and means are shown wherein an atomic beam containing two or more isotopes is exposed to radiation at a predetermined first wavelength to excite atoms of only one said isotope to a first intermediate excited state without substantially exciting atoms of other isotopes. These excited atoms are excited by a second radiation source at a second predetermined wavelength to a state of high principal quantum number, a Rydberg state, beneath the ionization continuum, again substantially without exciting atoms of said other isotopes to such high energy levels since substantially none of the other isotopes are in the intermediate excited state. From this bound atomic level only slightly below the ionization limit, the highly excited atoms are field ionized by electron tunneling and thence removed from the nonionized atoms by use of a moderate electric field.

Method and apparatus for field ionization for isotope separation

Highly sensitive method and apparatus for photon detection in the microwave and infrared regions of the electromagnetic energy spectrum are shown in which atoms of a material in the vapor state are excited to a first Rydberg energy level by use of radiation from one or more laser beams. The Rydberg excited material is subjected to the low energy radiation to be detected to induce therein an allowed electric dipole transition from said first to a second Rydberg energy level of the same or quite similar principal quantum number. Spontaneous high energy emission as a result of a distinctive radiative transition from said second Rydberg energy level is detected independently of other radiative transitions by conventional photodetector means such as a photomultiplier operable within the optical spectrum. The photomultiplier output provides a measure of said radiation to be detected. Tuning may be provided by the application of a magnetic field of selected strength to the atoms for Zeeman splitting of the first and second Rydberg energy levels. Also, for photon detection over a range of frequencies, a space or time varying magnetic field may be employed together with suitable photodetection means.

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Palo Alto, CA, United States of America

Robert M Hill