Interferometric Optical Gyroscope Research Articles

Interferometric optical gyroscope based on hybrid integrated optical transceiver module

Interferometric optical gyroscope based on hybrid integrated optical transceiver module

Enhanced phase estimation with coherently boosted two-mode squeezed beams and its application to optical gyroscopes

Quantum techniques, developed in recent decades, provide new approaches to achieving high-precision measurements beyond the classical bounds. In this paper, we theoretically demonstrate a metrology method for improving the sensitivity of the interferometric optical gyroscope, robust against the loss, by using coherent-light stimulated two-mode squeezed beams as the light source. The detection protocol is based on a simple intensity measurement, and the quantum noise is far below the shot-noise limit. The enhancement factors for different coherent light fields are analyzed in detail. Additionally, the influence of loss during the propagation in the optical path is studied, and the conditions for achieving sub-shot-noise measurement sensitivity are obtained. We also find that the phase sensitivity of the proposed gyroscope scheme becomes closer to the quantum Cram\'er-Rao bound with increasing of the photon number of the coherent beams.

Interferometric optical gyroscope based on an integrated silica waveguide coil with low loss.

An interferometric optical gyro (IOG) based on integrated devices are a promising alternative for miniaturized inertial sensors. However, improving their accuracy, which is determined by the sensing coil insertion loss, is crucial. In this work, an IOG is built using an integrated sensing coil produced from a 2.14-m-long SiO2 waveguide, the minimum bend radius and spacing of which are chosen to minimize the sensing coil insertion loss. The coil length is chosen by considering optimal detection limit constraints. Sinusoidal wave biasing modulation improves the system detection sensitivity. Finally, the IOG realizes the best yet reported bias drift of 7.32°/h.

Mode-assisted Silicon Integrated Interferometric Optical Gyroscope

The increasing demands in consumer electronics markets have promoted the development of chip-scale optical gyroscopes. In this study, a mode-assisted on-chip silicon-on-insulator interferometric optical gyroscope is proposed and assessed. The proposed gyroscope uses two different spatial modes propagating oppositely in the sensing waveguide coil to form a fixed phase difference that ensures the system operating at the best sensitive point. Compared with conventional schemes, it avoids the phase modulator and the circulator, which are not easy to be integrated in the same platform. The simulated results show that the detectable angular rate reaches 0.64 deg/s with a footprint of 3.85 × 10−3 m2. The experimental results validate the realization of the highly sensitive phase bias of the fabricated device.

Heterogeneous silicon photonics sensing for autonomous cars.

Heterogeneous silicon photonics is uniquely positioned to address the photonic sensing needs of upcoming autonomous cars and provide the necessary cost reduction for widespread deployment. This is because it allows for wafer-scale active/passive integration, including optical sources. We present our recent research and the development of interferometric optical gyroscopes and LiDAR sensors. More specifically, we show a fully integrated gyroscope front-end occupying an area of only 4.5 mm2. We also show the first dense pitch optical phased array using heterogeneous phase shifters. The 4 µm pitch heterogeneous phase shifters provide very low V2π of only 0.35-1.4 V across 200 nm, low residual amplitude modulation of only 0.1-0.15 dB for 2π phase shift, extremely low static power consumption (<3 nW), and high speed (> 1 GHz). All of these factors make them ideal for next-generation LiDAR systems that employ optical phased arrays.

Silicon Integrated Interferometric Optical Gyroscope

Miniaturized and low-cost optical gyroscopes are urgently required for emerging applications in consumer electronics market. In this paper, we proposed a theoretical analysis and preliminary experiment results for integrated interferometric optical gyroscope based on the silicon-on-insulator (SOI) platform for the first time. The gyroscope is based on the Sagnac effect and composed of coiled multimode waveguides to reduce propagation loss and the footprint. The sensitivity of the sensing part is fully investigated in terms of waveguide loss, gyroscope footprint, crossing numbers for coiled waveguides, as well as the waveguide cross section. The experimental results show that gyroscope sensitivity is 51.3 deg/s with a footprint of 600 μm × 700 μm.

Interferometric Optical Gyroscope Based on an Integrated Si3N4 Low-Loss Waveguide Coil

We describe the measurement and characterization of an interferometric optical gyroscope that uses an integrated 3-m large-area silicon nitride waveguide coil with waveguide loss <0.78 dB/m that is compatible with wafer-scale integration. The angle random walk and bias instability were measured to be 8.52°/h1/2 and 58.7°/h, respectively. The measured performance is comparable to that of a commercial rate grade gyroscope, demonstrating that chip-scale integration is a feasible path to low cost, low power, compact implementation of optical gyroscope, and realization of longer coils will expand use of this technology to more demanding navigation applications.

Integrated optical driver for interferometric optical gyroscopes.

We present the first chip-scale "integrated optical driver" (IOD) that can interrogate with a sensing coil to realize an interferometric optical gyroscope. The chip comprises a light source, three photodiodes, two phase modulators and two 3-dB couplers within an area of 4.5 mm2. This allows for a significant reduction in size, weight, power consumption and cost of optical gyroscopes.

Frequency modulated lasers for interferometric optical gyroscopes.

We study the use of frequency modulated lasers in interferometric optical gyroscopes and show that by exploiting various frequency modulation signals, the laser coherence can be controlled. We show that both angle random walk and bias stability of an interferometric optical gyroscope based on laser sources can be improved with this technique.