New design for a high performance optically pumped cesium beam tube

Abstract

An optically pumped cesium beam resonator has been designed including three successive magnetic field regions. The optical interactions take place in the first and third regions, where the magnetic field has the required value of 3x10(-5) T. The microwave interaction occurs in the intermediate region, where the value of the C-field is typically set to 4x10(-6) T. It has been verified that the magnetic field profile along the cesium beam does not induce Majorana transitions. Using a single laser diode emitting at 852 nm with a linewidth of about 30 MHz, the resonator gives an excellent amplitude signal to noise ratio equal to 20000 in a 1-Hz bandwidth.

Performance demonstration of a compact, single optical frequency Cesium beam clock for space applications

“…Birefringent optical elements depolarize the laser beams in the PU and the DU [9] for the used D2 transition. A polarization gradient along the atomic beam increases the efficiency of the optical pumping in the PU without requiring a strong static magnetic field [10], or a 1D optical molasses [11]. The optical power in both the PU and DU was optimized for maximum signal-to-noise ratio (SNR) in order to increase the frequency stability of the standard.…”

Light shift in an optically pumped caesium-beam frequency standard

“…where is the spontaneous decay probability at the transition and is the time of interaction of the atom with the pumping laser beam. The quantities can be found by numerical solution of the density matrix equations for a speci c interaction scheme [8][9][10][11][12]. The probability of the spontaneous emission of a given polarization at the transition can be written as where the spontaneous decay probability at the hyper ne structure transition , is de ned by the spontaneous decay probability at the ne structure transition P S , and the radiative lifetime ns.…”

Laser-induced noise contribution due to imperfect atomic state preparation in an optically pumped caesium beam resonator

“…Our beam resonator is divided into three magnetic field regions with their own magnetic shield and independent trimming coils (Giordano et al 1991). This apparatus provides a weak static magnetic induction in the microwave interaction region (about 7 µT) and higher static magnetic induction in the two optical interaction regions (typically 50 µT) in order to ensure a good efficiency of the optical pumping (Théobald et al 1989).…”