title: Polarization orthogonalizer for a pair of laser beams with nearly equal frequencies.
abstract: We have demonstrated a device to produce an overlapping pair of orthogonally polarized laser beams with a 3 GHz frequency offset out of a single laser beam containing the two frequency components with the same linear polarization. Our design is based on a Michelson interferometer formed by a polarizing beam splitter and two quarter-waveplates. Such a device can be used to make the polarization states of a carrier and a sideband produced through modulation mutually orthogonal. An orthogonally polarized pair of coherent laser beams can be used for an interferometric measurement of a small displacement in a heterodyne scheme or to produce a large-contrast coherent population trapping signal from alkali metal atoms. As a demonstration we used the device to achieve 40% contrast for a coherent population trapping signal from a rubidium vapor cell.
authors.affiliation: Department of Physics, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Sin Hyuk
authors.initials: SH
authors.lastname: Yim
authors.forename: T H
authors.initials: TH
authors.lastname: Yoon
authors.forename: D
authors.initials: D
authors.lastname: Cho