Single-element dual-interferometer for precision inertial sensing
Yichao Yang, Kohei Yamamoto, Victor Huarcaya, Christoph Vorndamme, Daniel Penkert, Germán Fernández Barranco, Thomas S Schwarze, Juan Jose Esteban Delgado, Mori… 展开作者
Yichao Yang, Kohei Yamamoto, Victor Huarcaya, Christoph Vorndamme, Daniel Penkert, Germán Fernández Barranco, Thomas S Schwarze, Juan Jose Esteban Delgado, Moritz Mehmet, Jianjun Jia, Gerhard Heinzel, Miguel Dovale Álvarez
Tracking moving masses in several degrees of freedom with high precision and large dynamic range is a central aspect in many current and future gravitational physics experiments. Laser interferometers have been established as one of the tools of choice for such measurement schemes. Using sinusoidal phase modulation homodyne interferometry allows a drastic reduction of the complexity of the optical setup, a key limitation of multi-channel interferometry. By shifting the complexity of the setup to the signal processing stage, these methods enable devices with a size and weight not feasible using conventional techniques. In this paper we present the design of a novel sensor topology based on deep frequency modulation interferometry: the self-referenced single-element dual-interferometer (SEDI) inertial sensor, which takes simplification one step further by accommodating two interferometers in one optic. Using a combination of computer models and analytical methods we show that an inertial sensor with sub-picometer precision for frequencies above 10 mHz, in a package of a few cubic inches, seems feasible with our approach. Moreover we show that by combining two of these devices it is possible to reach sub-picometer precision down to 2 mHz. In combination with the given compactness, this makes the SEDI sensor a promising approach for applications in high precision inertial sensing for both next-generation space-based gravity missions employing drag-free control, and ground-based experiments employing inertial isolation systems with optical readout.
We present a compact, fibre-coupled interferometer with high sensitivity and a large working range. We propose to use this interferometer as a readout mechanism for future inertial sensors, removing a major limiting noise source, and in precision positioning systems. The interferometers peak sensitivity is $2 \times 10^{-{14}}$ m/${\sqrt{\rm{Hz}}}$ at 70 Hz and $8 \times 10^{-{11}}$ m/$\sqrt{\rm{Hz}}$ at 10 mHz. If deployed on a GS-13 geophone, the resulting inertial sensing output will be dominated by suspension thermal noise from 50 mHz to 2 Hz.
We present a compact heterodyne laser interferometer developed for high-sensitivity displacement sensing applications. This interferometer consists of customized prisms and waveplates assembled as a quasi-monolithic unit to realize a miniaturized system. The interferometer design adopts a common-mode rejection scheme to provide a high rejection ratio to common environmental noise. Experimental tests in vacuum show a displacement sensitivity level of 11 pm/rtHz at 100mHz, and as low as 0.6pm/rtHz above 1Hz. The prototype unit has a size of 20mm X 20mm X 10mm and weighs 4.5 grams, which allows s…
We discuss the design of quantum hybrid inertial sensor that combines an optomechanical inertial sensor with the retro-reflector of a cold atom interferometer. This sensor fusion approach provides absolute and high accuracy measurements with cold atom interferometers, while utilizing the optomechanical inertial sensor at frequencies above the repetition rate of the atom interferometer. This improves the overall measurement bandwidth as well as the robustness and field deployment capabilities of these systems. We evaluate which parameters yield an optimal acceleration sensitivity, from which we…
Single-Element Dual-Interferometer for Precision Inertial Sensing: Sub-picometer Structural Stability and Performance as a Reference for Laser Frequency Stabilization
We propose a method to track signals from quadrant photodiodes (QPD) in heterodyne laser interferometers that employ digital phase-locked loops for phase readout. Instead of separately tracking the four segments from the QPD and then combining the results into length and Differential Wavefront Sensing (DWS) signals, this method employs a set of coupled tracking loops that operate directly on the combined length and angular signals. Benefits are increased signal-to-noise ratio in the loops and the possibility to adapt the loop bandwidths to the different dynamical behavior of the signals being …
We report on our progress in the construction of a continuous matter-wave interferometer for inertial sensing via the non-destructive observation of Bloch oscillations. At the present stage of the experiment, around $10^5$strontium-88 atoms are cooled down to below 1$μ$μK. Pumped by lasers red-tuned with respect to the 7.6 kHz broad intercombination transition of strontium, the two counterpropagating modes of the ring cavity form a one-dimensional optical lattice in which the atoms, accelerated by gravity, will perform Bloch oscillations. The atomic motion can be monitored in real-time via its…
Concatenated modal interferometers based multipoint sensing system for detection of instantaneous amplitude, frequency, and phase of mechanical vibrations is proposed and demonstrated. The sensor probes are fabricated using identical photonic crystal fiber (PCF) sections and integrated along a single fiber channel to act as a compact and efficient sensing system. Individual probes operate independently producing a resultant signal that is a superposition of each interferometer response signal. By analyzing the resultant signals, information about the measurand field at each location is realize…
We present a novel inertial-isolation scheme based on six degree-of-freedom (6D) interferometric sensing of a single reference mass. It is capable of reducing inertial motion by more than two orders of magnitude at 100\,mHz compared with what is achievable with state-of-the-art seismometers. This will enable substantial improvements in the low-frequency sensitivity of gravitational-wave detectors. The scheme is inherently two-stage, the reference mass is softly suspended within the platform to be isolated, which is itself suspended from the ground. The platform is held constant relative to the…
High-precision inertial sensing and gravity sensing are key in navigation, oil exploration, and earthquake prediction. In contrast to prior accelerometers using piezoelectric or electronic capacitance readout techniques, optical readout provides narrow-linewidth high-sensitivity laser detection along with low-noise resonant optomechanical transduction near the thermodynamical limits. Here an optomechanical inertial sensor with 8.2micro-g/Hz^1/2 velocity random walk (VRW) at acquisition rate of 100 Hz and 50.9 micro-g bias instability is demonstrated, suitable for consumer and industrial grade …
Atom interferometry has become one of the most powerful technologies for precision measurements. To develop simple, precise, and versatile atom interferometers for inertial sensing, we demonstrate an atom interferometer measuring acceleration, rotation, and inclination by pointing Raman beams toward individual faces of a pyramidal mirror. Only a single diode laser is used for all functions, including atom trapping, interferometry, and detection. Efficient Doppler-sensitive Raman transitions are achieved without the velocity selecting the atom sample, and with zero differential AC Stark shift b…
Cold-atom inertial sensors target several applications in navigation, geoscience and tests of fundamental physics. Reaching high sampling rates and high inertial sensitivities, obtained with long interrogation times, represents a challenge for these applications. We report on the interleaved operation of a cold-atom gyroscope, where 3 atomic clouds are interrogated simultaneously in an atom interferometer featuring a 3.75 Hz sampling rate and an interrogation time of 801 ms. Interleaving improves the inertial sensitivity by efficiently averaging vibration noise, and allows us to perform dynami…
The research on cold-atom interferometers gathers a large community of about 50 groups worldwide both in the academic and now in the industrial sectors. The interest in this sub-field of quantum sensing and metrology lies in the large panel of possible applications of cold-atom sensors for measuring inertial and gravitational signals with a high level of stability and accuracy. This review presents the evolution of the field over the last 30 years and focuses on the acceleration of the research effort in the last 10 years. The article describes the physics principle of cold-atom gravito-inerti…
