Daniil G. Gilev

Fibre-optic resonators enable the miniaturization of fibre-optic gyroscopes (FOGs) by reducing the dimensions of sensing elements. This is achieved by repeatedly passing light through the optical path within the resonator. This paper presents a mathematical model of the optical field interactions in a resonator-interferometric FOG with a broadband light source, which analyzes the effect of insertion loss and the amplitude-frequency response of a sensing element on the formation of the gyroscope output signal. For the first time, we derive an analytical formula for the optical scheme of a gyroscope, which links the output radiation to the Sagnac effect and the modulation signal. A mathematical model is then developed to demonstrate the formation of the output signal based on the optical and mechanical parameters of the scheme and to predict the performance of the gyroscope. The experimental validation involved an RFOG with a resonator diameter of 40 mm and an optical fibre length of 50 m, tested under varying angular velocities and normal environmental conditions. The results show a scale factor deviation of less than 1% in the range of ±200°/s, confirming the accuracy of the model. The bias instability (BI) was 10°/h, while the angle random walk (ARW) was 1.6°/√h. The presented analysis and model facilitate the precise optimisation of resonator-based FOGs.

We discussed the possibility of using SPUN fiber in fiber-optic magnetometers. Such a fiber has a property to preserve the circular polarization of radiation passing through it. When SPUN fiber is affected by external factors, the length of polarization beats changes. It is shown that external mechanical effects and the applied magnetic field make the main contribution to the change in the length of polarization beats of SPUN fiber. In this paper a layout scheme is presented, which allows to register an external magnetic field of the order of 0.01 T.

Measurements of the half-wave voltage of the integrated-optical phase modulator on LiNbO3 were carried out in the temperature range from –40 to +60 °C. The measurements were carried out by two methods using the Sagnac and Mach-Zehnder interferometers. The temperature coefficients of the half-wave voltage change obtained in the experiments agree with the theoretical ones.

Simple measures to improve the signal-to-noise ratio of optical frequency domain reflectometer (OFDR) readings are described. After applying a two-stage optical amplification of the backscattered signal, as well as eliminating the source of spurious reflections, it was possible to increase the signal-to-noise ratio of the frequency domain trace from 8 to 19 dB. This technique can be applied in fiber optic sensors and metrology of fiber optic and integrated optical elements.

In the work, a fiber-optic resonator (FOR) was studied, which is used as a sensitive element of the angular velocity sensor. The measured operating parameters of the RVO are given and the dependence of the resonant frequency shift on the angular velocity is found. The developed layout made it possible to measure the minimum sensitivity to the angular velocity of this resonator and to evaluate the maximum measurement range. An estimate of the angular velocity measurement range gives values from minus 600,000 °/s to minus 10 °/s and from 10 °/s to 600,000 °/s.

Reducing the dimensions of optical gyroscopes is a crucial task and resonant fiber optic gyroscopes are promising candidates for its solution. The paper presents a prototype of a miniature resonant interferometric gyroscope of a strategic accuracy class. Due to the use of passive optical elements in this gyroscope, it has a great potential for miniaturization, alongside a low production cost and ease of implementation, since it does not require many feedback loops. The presented prototype shows results on a zero instability of 20°/h and an angle random walk of 0.16°/√h. A theoretical model explaining the nature of the multipath interference of resonant spectra and establishing the relationship between the resonator parameters and the output parameters of the presented prototype is proposed. The results predicted are in agreement with the experimental data. The prototype gyroscope demonstrates a scale factor instability and a change in the average signal level, which is due to the presence of polarization non-reciprocity, occurring due to the induced birefringence in the single-mode fiber of the contour. This problem requires further investigation to be performed.

Today, the task of developing microoptical gyroscopes is topical. Usually, tunable lasers with a built-in frequency stabilization system are used in such gyroscopes. They are comparatively bulky, which hinders the real miniaturization of optical gyroscopes. We propose a new approach implemented by using a Mach–Zehnder modulator with a passive ring resonator connected to one of its arms. This makes it possible to obtain a mutual configuration and makes the use of a tunable laser optional. Two ring resonators made of the polarization-maintaining fiber, suitable for use as sensitive elements of a gyroscope, were realized and investigated. Their Q-factor is equal to 14.5 × 10⁶ and 28.9 × 10⁶. The maximum sensitivity of the proposed method when using the described resonators is 3.2 and 1.8 °/h, respectively. The first experimental setup of a resonator gyroscope implementing this approach has been manufactured and analyzed. When measuring the rotation speed by the quasi-harmonic signal span and its phase, the measurement accuracy was approximately 11 and 0.4 °/s, respectively.

Fiber-optic ring resonators can be used in various fields of science and technology as miniature sensors and sensors of physical quantities: an optoelectro

Polarization maintaining fibers (PMF) are used in various fields of photonics and telecommunications, so the study of the propagation of optical radiation

In order to develop a new type of angular velocity sensor based on a fiber optic resonator, various optical circuits are being developed that will be sensitive to rotation. This paper presents an increase in the sensitivity of a fiber-optic resonant gyroscope through the use of various methods for processing the resonant peak.