Nobuo Nishimiya | PubMed Health

PubMed2004

Frequency measuring system using mirror gap stabilized Fabry-Perot interferometer.

The mirror gap of a Fabry-Perot interferometer was stabilized with two laser diodes; one locked to the line frequency 385,243,555.14445 MHz of the F=3<--1 in 5D(3/2)<--5S(1/2) (87Rb) and the other to the 385,284,566.3663 MHz of the F=4<--2 in 5D(5/2)<--5S(1/2) (87Rb) [Opt. Commun. 102 (1993) 432]. The length of the mirror gap was adjusted to generate the zero-cross points simultaneously at both of the two line positions. The fringe signals obtained from an interferometer thus stabilized can be used as frequency markers having accuracies of the order of 10(10) depending on the finesse of the interferometer used. Based on measurement using Cs D1 hyperfine lines reported by Udem et al. [Phys. Rev. Lett. 82 (1999) 3568], the uncertainty of markers in the region 50 THz apart from the reference lines is +/- 5 MHz.

Data Interpretation, Statistical↗

PubMed2002

Saturated absorption spectroscopy of Xe using a GaAs semiconductor laser.

Doppler-free absorption spectrum from 5P(5)6S to 5P(5)6P transitions of Xe in a hollow cathode discharge was measured in the wavelength region from 810 to 910 mn. The saturated dip signals detected by a frequency modulated probe beam were doubly AM-modulated by a pump beam chopped using a conventional mechanical chopper. The Doppler background was greatly reduced by detection using a second lock in amplifier synchronous to the chopping signal. The isotope shifts of even mass (136-128)Xe in natural abundance were resolved for the five transitions from the metastable states of J = 2 and 0, while in the transitions from the J = 1 states were partially resolved. The nuclear magnetic and quadrupole hyperfine coupling constants of 131Xe and 129Xe determined are listed with those reported previously. The specific mass shifts and the field shifts were estimated using the relation given by King's diagram and compared with those obtained from the changes in the mean square-radii of the nuclear charge distribution.

Arsenic↗