Integrated Optical Resonator Research Articles

Advancements in Optical Resonator Stability: Principles, Technologies, and Applications

This paper provides an overview of the study of optical resonant cavity stability, focusing on the relevant principles, key technological advances, and applications of optical resonant cavities in a variety of high-precision measurement techniques and modern science and technology. Firstly, the vibration characteristics, thermal noise, and temperature characteristics of the reference cavity are presented. Subsequently, the report extensively discusses the advances in key technologies such as mechanical vibration isolation, thermal noise control, and resistance to temperature fluctuations. These advances not only contribute to the development of theory but also provide innovative solutions for practical applications. Typical applications of optical cavities in areas such as laser gyroscopes, high-precision measurements, and gravitational wave detection are also discussed. Future research directions are envisioned, emphasising the importance of novel material applications, advanced vibration isolation technologies, intelligent temperature control systems, multifunctional integrated optical resonator design, and deepening theoretical models and numerical simulations.

Bloch surface wave ring resonator based on porous silicon

In this work, we experimentally demonstrate confined modes in a Bloch surface wave (BSW) ring resonator. We fabricate and characterize a ring resonator with a radius R = 105 μm on a truncated periodic porous silicon multilayer. We show resonant modes around 1.5 μm with quality factors exceeding 103. These results suggest that this platform is promising to develop integrated optical resonators based on BSWs.

Optofluidic a-Si:H-Based Photonic Lab-on-Chip With Dispersion Engineered Resonance Spectra

We report on a lab-on-chip sensor system based on integrated-optical resonators. The photonic components were realized in CMOS-process compatible amorphous silicon and the microfluidic interface enabling directed analyte transport was fabricated with soft-lithography technology. The developed sensor features optical resonators with dispersion engineered resonance spectra (DERS) to match optical resonance peaks over a wavelength region of several free spectral ranges. Resonance shifts caused by changes in refractive index of the investigated analyte are tracked by red-shifting a reference spectrum through the thermo-optic effect using electrical micro-heaters. With the DERS preserving the unambiguousness of the direct proportional relation between resonance shift and necessary heating power, this sensing principle enables direct electronic readout of analyte property changes. The sensor system therefore reduces the number and the size of peripheral devices usually necessary for the analysis of integrated optical devices, resulting in a broader range of potential application scenarios.

Temperature-dependent, polarization-induced bias errors in a resonator integrated optical gyroscope

The performance of a resonator integrated optical gyroscope (RIOG) is inevitably influenced by polarization noise. In this work, the effects of temperature-dependent polarization on the performances of an integrated optical resonator (IOR) and a RIOG are formulated mathematically and analyzed. Firstly, resonant curves with different polarization extinction ratios (PERs) and different temperature fluctuations are demonstrated. The main performances of the IOR, i.e. depth and full width at half maximum (FWHM), are not only influenced by the waveguide birefringence, but also by the intensity coupling coefficient of the couplers, both of which change with the variation of temperature. Secondly, the relationship between the variation of temperature and the variation of depth, as well as the FWHM, are obtained. Thirdly, in order to evaluate the zero bias error caused by the temperature-dependent polarization, resonant asymmetry ratio (RAR) is introduced, which is strongly dependent on the temperature fluctuation. A relationship between the bias error caused by the polarization and the temperature fluctuation is proposed. A large PER of the input beam and a high temperature stability are required to reduce the bias error and achieve a high bias stability of the silica RIOG.

Sensitivity improvement of resonator integrated optic gyroscope by double-electrode phase modulation

In this paper, a novel method to improve the sensitivity of RIOGs is demonstrated by double-electrode phase modulation (DPM) technology. The scale factor of RIOGs with single-electrode phase modulation (SPM) and DPM are theoretically analyzed and calculated. The relationship between the slope rate in the linear region adjacent to the zero-offset point and the amplitudes of the triangle waveform with SPM and DPM are obtained; the RIOG's highest sensitivity appears when the triangle waveforms have amplitudes of 45.9 and 22.95V, respectively. Compared with the SPM, the DPM shows great advantage in improving the RIOG scale factor, as well as its bias stability. Moreover, in measurements using the RIOG experimental setup, the scale factor is significantly increased from 1.49 to 2.76, which is coincident with the simulation result. The test results for long-term bias stability demonstrate that the DPM has the advantage of improving the signal-to-noise ratio (SNR); significantly, the RIOG long-term bias stability is greatly improved from 0.61 to 0.49deg/s, which is the best long-term stability result reported to date, to the best of our knowledge, for a waveguide-type integrated optical resonator (IOR).

Analysis of Intensity Variation of Laser in Resonator Micro-Optic Gyro

The paper describes the basic principle and structure of the resonator micro-optic gyro (RMOG), the influence of intensity variation of laser is analyzed for the first time. The relationship between the light intensity input the integrated optical resonator (IOR) and the slope at working range is simulated and analyzed by the optical field overlapping method. The amplitudes of the output square waveforms with different zero biases are simulated and analyzed. The experimental setup is constructed and tested, the test result shows that in order to reach the limited ultimate sensitivity of 15.5 deg/h, it is necessary to restrict the zero bias within 8.1 deg/s under open-loop output scheme.

Effect of intensity variation of laser in resonator integrated optic gyro

The performance of the resonator integrated optic gyro (RIOG) is inevitably influenced by the intensity variation of the laser. In this work, the effect of intensity variation of the laser is mathematically formulized, analyzed, and experimentally validated, to our knowledge for the first time. First, the demodulated curves with different light intensities input of the integrated optical resonator (IOR) are simulated; the relationship between the slope of the demodulated curve near the resonant point and the light intensity input of the IOR is obtained. Second, the amplitudes of the output square waveforms with different zero biases are demonstrated, and it can be concluded that the effect of intensity variation has a high correlation with the nonzero bias between the clockwise and counterclockwise resonant frequency. Third, the experimental setup is constructed and the related measurements are performed, the test results are in good agreement with the analytical and numerical simulation, and in order to reach the limited ultimate sensitivity of the RIOG, it is necessary to restrict the nonreciprocal zero bias within 8.1 deg/s under an open-loop output scheme. Furthermore, to eliminate the noise induced by intensity variation of the laser and realize a high performance RIOG, a closed-loop operation is required.