Method for velocimetry of cold atoms

Abstract

We describe our use of recoil-induced resonances or stimulated optical Compton scattering to measure the velocity distribution of laser-cooled cesium atoms in one dimension. The technique works well at velocities near 1 cm/s, is insensitive to the effects of light shifts or stray fields, requires only a few mm of work space, and may be completed in 1 ms. It may be extended to allow the measurement of velocity distributions in three dimensions and for in situ measurements in optical molasses, traps, or lattices. Our measurements are compared with traditional ballistic measurements in the same apparatus.PACS number(s): 32.80. Pj, 42.50.Vk

Nonvolatile optical memory via recoil-induced resonance in a pure two-level system

“…As predict in [15], and contrary to EIT or CPO resonances, the probe transmission spectrum is not very sensitive to conventional power broadening, which is a characteristic of RIR. Although in [16] some induced heating of the atomic sample has been observed for increasing coupling beam intensity, we believe the much higher temperature of our MOT, associated with a much shorter duration of our coupling beam pulse, prevent the observation of this indirect power broadening mechanism in the RIR spectrum. However, previous work [18] has reported a much stronger dependence on the RIR linewidth with the trapping beam intensity…”

“…The RIR memory can also operate in a pure TLS but involves a transition between external degrees of freedom of the atom, which are excited by a strong Coupling (C) beam and a weak Probe (P) beam [15][16][17]. The RIR can be observed when the probe and the coupling beams having the same optical polarization, but wavevectors and frequencies differing, respectively, by q = k P − k C and δ = ω P − ω C , couple to different atomic external states having momentum p and p ±h q [15].…”

Comparison of recoil-induced resonances and the collective atomic recoil laser

“…Among topics that have been discussed that fall into this category are Recoil-Induced Resonances (RIR) [1][2][3][4][5][6][7][8][9] and the Collective Atomic Recoil Laser (CARL) [10][11][12][13]. These processes appear to have much in common, although they are described quite differently.…”

Opto-mechanical estimation of micro-trap with cold atoms via nonlinear stimulated Raman scattering spectrum

“…Due to atomic recoil motion, atomic oscillations in the micro-trap will be actuated and closely entangled with resonant cavity modes through scattering in atomic absorption-emission cycles [29]. The dynamical backaction of the atomic oscillation dramatically modifies the optical spectrum and its intensity is further enhanced by a synchronization of the individual oscillators [36] (equivalent to building a collective mechanical mode).…”

“…In order to estimate the trapping parameters of microtraps, many different methods have been proposed, such as dynamical methods on atomic oscillations [21][22][23], the trap-loss rate method of atomic collisions [24], the free-expansion method by temperature measurement [25] and optical spectroscopic methods via stimulated Raman scattering (SRS) [26][27][28] or recoil induced resonance on atomic velocity [29][30][31]. Because the field-induced microtrap on atom chips is relatively flexible on small scales, above mentioned mechanical methods on this system are difficult to carry out in a high resolution limit.…”