An Atomic Fabry-Perot for the Generation and Measurement of Ultracold Wavepackets

A matter-wave Fabry-Perot (FP) for the generation of ultracold wavepackets could be implemented using an optical double barrier. Observation of the transmission spectrum of a single such FP becomes impractical for wavepacket temperatures above about 100pK. The resonances are washed out due to the velocity width of the incident wavepacket being larger than the width of the resonances. We propose a scheme for using a second atomic FP with a tunable cavity length to characterize the filtering properties of the first. Gross-Pitaevskii (GP) simulations of a ⁸⁷Rb BEC interacting with double-Gaussian potentials show that evidence of resonant transmission can be observed using this scheme. The GP simulations use experimentally achievable parameters of a 1nK ⁸⁷Rb BEC of a few thousand atoms, incident on barriers with a 1/e² radius of 1.3 µm. With these parameters, BECs containing a few hundred atoms could be generated at a temperature less than 50pK. We plan to realize this scheme experimentally using a spatial light modulator to manipulate the optical potential for the tunable cavity length matter-wave FP.

*NSERC and the Fetzer Franklin Fund of the John E. Fetzer Memorial Trust