Optical pumping of hyperfine states by light pulsed at the zeeman frequency

摘要

1,057,580. Photo-electric investigation of quantum systems. VARIAN ASSOCIATES. Nov. 4, 1964 [Dec. 26, 1963], No.45019/64. Heading G1A. [Also in Division H3] Atoms of sodium vapour in an absorption cell 16 are optically pumped by light from a sodium lamp 10 pulsed at the Zeeman frequency or a sub-multiple thereof, the light passing to the cell through a circular polarizer 17, and the cell being arranged in a steady magnetic field H 0 and a R. F. magnetic field H 1 in the same direction produced by the excitation of a resonant cavity 18 at a hyperfine frequency, e.g. 1772 Mc/s. The cell may be used to regulate the frequency of a crystal oscillator 24 the output of which is phase modulated in unit 26 at 10 c/s and synthesized and/or multiplied up to the hyperfine frequency. Light passing through the cell is detected by a photo-cell 36 feeding a filter 38 and amplifier 40. A detector 41 recovers the 10 c/s and 20 c/s signal components, the latter being rejected by filter 43 and the former detected by detector 42 which provides an error signal to a servo-amplifier 44 controlling the tuning of oscillator 24. Alternatively the cell may be used in an optically pumped magnetometer, spectrometer or maser. The cell may use hydrogen, potassium or rubidium instead of sodium.