Compact atom interferometer using single laser

Xiaojing Wu, Fei Zi, Ryan Bilotta +2 more

Sheng‐wey Chiow, Nan Yu

A laser system for a light-pulse atom interferometer typically includes a number of laser sources for cooling and for atom optics to meet different frequency detuning requirements at different stages of a measurement sequence. The number of laser units required makes the achievable minimum size and power of the instrument challenging, especially for space applications. We demonstrate a compact cesium atom interferometer operated by only a single laser. This is achieved by dynamically changing the laser output frequency while maintaining spectroscopic reference to an atomic transition. We are able to generate cold atoms and obtain atom interferometer fringes all with the same laser.

Jongmin Lee, Roger Ding, Justin Christensen +16 more

Abstract The extreme miniaturization of a cold-atom interferometer accelerometer requires the development of novel technologies and architectures for the interferometer subsystems. We describe several component technologies and a laser system architecture to enable a path to such miniaturization. We developed a custom, compact titanium vacuum package containing a microfabricated grating chip for a tetrahedral grating magneto-optical trap (GMOT) using a single cooling beam. The vacuum package is integrated into the optomechanical design of a compact cold-atom sensor head with fixed optical components. In addition, a multichannel laser system driven by a single seed laser has been implemented with time-multiplexed frequency shifting using single sideband modulators, reducing the number of optical channels connected to the sensor head. This laser system architecture is compatible with a highly miniaturized photonic integrated circuit approach, and by demonstrating atom-interferometer operation with this laser system, we show feasibility for the integrated photonic approach. In the compact sensor head, sub-Doppler cooling in the GMOT produces 15 μK temperatures, which can operate at a 20 Hz data rate for the atom interferometer sequence. After validating atomic coherence with Ramsey interferometry, we demonstrate a light-pulse atom interferometer in a gravimeter configuration without vibration isolation for 10 Hz measurement cycle rate and T = 0 - 4.5 ms interrogation time, resulting in Δg/g = 2.0e-6. All these efforts demonstrate progress towards deployable cold-atom inertial sensors under large amplitude motional dynamics.

Patrick Cheinet, Franck Pereira dos Santos, T. Petelski +5 more

Ki-Se Lee, Sang-Bum Lee, Sang Eon Park +2 more

A new robust laser system for mobile atom interferometers is reported. Phase modulation of a single diode laser provide two phase-coherent frequencies necessary for the Raman transition in light-pulse atom interferometers. Additional laser frequencies generated by the phase modulation, which would disturb the phase of atom interferometers, is filtered by a Fabry-Perot cavity. The two sidebands of the phase-modulated light is tuned to the adjacent resonances of the cavity and the carrier mode and even-order higher sidebands are filtered. The laser beam is then fed to a single tapered amplifier, and the two sidebands are both amplified without mode competition. The phase noise is lower than that of a state-of-the-art optically phase-locked external-cavity diode laser (-135 dBrad2/Hz at 10 kHz). This technique can be used in all-fiber-based laser systems for future mobile atom interferometers. The laser system has advantage of low phase noise, high mechanical stability, low power consumption and compactness.

Sébastien Merlet, Laurent Volodimer, M. Lours +1 more