Salvi L, Cacciapuoti L, Tino G M, Rosi G
Dipartimento di Fisica e Astronomia and LENS, Università di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy.
European Space Agency, Keplerlaan 1, 2201 AZ Noordwijk, Netherlands.
Phys Rev Lett. 2023 Sep 8;131(10):103401. doi: 10.1103/PhysRevLett.131.103401.
We demonstrate a novel scheme for Raman-pulse and Bragg-pulse atom interferometry based on the 5S-6P blue transitions of ^{87}Rb that provides an increase by a factor ∼2 of the interferometer phase due to accelerations with respect to the commonly used infrared transition at 780 nm. A narrow-linewidth laser system generating more than 1 W of light in the 420-422 nm range was developed for this purpose. Used as a cold-atom gravity gradiometer, our Raman interferometer attains a stability to differential acceleration measurements of 1×10^{-8} g at 1 s and 2×10^{-10} g after 2000 s of integration time. When operated on first-order Bragg transitions, the interferometer shows a stability of 6×10^{-8} g at 1 s, averaging to 1×10^{-9} g after 2000 s of integration time. The instrument sensitivity, currently limited by the noise due to spontaneous emission, can be further improved by increasing the laser power and the detuning from the atomic resonance. The present scheme is attractive for high-precision experiments as, in particular, for the determination of the Newtonian gravitational constant.
我们展示了一种基于(^{87}Rb)的(5S - 6P)蓝光跃迁的拉曼脉冲和布拉格脉冲原子干涉测量新方案，与常用的(780nm)红外跃迁相比，该方案因加速度导致的干涉仪相位增加了约(2)倍。为此开发了一种窄线宽激光系统，可在(420 - 422nm)范围内产生超过(1W)的光。用作冷原子重力梯度仪时，我们的拉曼干涉仪在(1s)内对差分加速度测量的稳定性达到(1×10^{-8}g)，积分时间为(2000s)后达到(2×10^{-10}g)。当在一阶布拉格跃迁上运行时，干涉仪在(1s)内的稳定性为(6×10^{-8}g)，积分时间为(2000s)后平均为(1×10^{-9}g)。目前该仪器的灵敏度受自发发射噪声限制，可通过增加激光功率和与原子共振的失谐来进一步提高。本方案对高精度实验具有吸引力，特别是对于牛顿引力常数的测定。
