LAUSR

The wave-front aberration of Raman beams induces phase noise in atom interferometers and thus limits the performance of atom interferometers. We theoretically analyze the wave-front-aberration phase noise in weakequivalence-principle tests using dual-species atom interferometers, and propose an expansion-rate-selection method to suppress the wave-front-aberration phase noise in both isotopic and nonisotopic atom interferometers. The suppression ratio is about 10 at the expense of half the number of atoms. The simulation based on appropriate experimental parameters shows that thewave-front aberration caused standard deviations to the Eotvos coefficient in weak-equivalence-principle tests using Rb-85-Rb-87 and K-41-Rb-87 are 1.3 x 10(-14) and 3.0 x 10(-13). Better results can be obtained by improving the wave-front quality and utilizing atom cloud with lower temperature. The analysis and suppression of wave-front-aberration phase noise will be useful for the design of high-precision atom interferometer-based weak-equivalence-principle tests both on ground and in space.