【摘要】 地表运动的旋转量观测在地震学、地球物理学及工程勘察等研究中具有重要意义，基于Sagnac效应的光纤陀螺由于其全固态、高灵敏度和宽频响特性等优势，受到旋转地震仪研究和开发的广泛关注．为了提高光纤旋转地震仪的灵敏度一般采用长光纤环，然而随着光纤长度的增加，光纤环内的热相位噪声、光源的相对强度噪声等限制了其灵敏度性能提高．本文针对影响光纤旋转地震仪灵敏度的噪声展开了深入分析，利用保偏光纤的快慢轴提出了双偏振工作方案，对其光学结构和解调算法进行了理论分析，结果表明该方案可有效抑制热相位噪声与光源相对强度噪声．在此基础上，研制了三分量双偏振光纤旋转地震仪DP-Rot3C，并对其进行了静态测试和动态测试．结果显示，该仪器的灵敏度达到了■，与法国Bluseis-3A相当，且在0.01～125Hz频率范围内响应平坦，在-300～+300°/s的量程范围内非线性度小于6ppm (1ppm=0.0001%），具有高精度、宽频带、大量程、高线性度的特性．DP-Rot3C还运用于人工主动源观测、高铁地震观测、天然地震观测等领域，为工程勘探、地震研究等应用提供了高精度观测地表运动旋转量的工具．更多还原

【Abstract】 The observation of the rotation of surface motion is of great significance in seismology,geophysics,engineering exploration,and other research fields.Interferometer fiber optic gyroscopes based on the Sagnac effect have attracted extensive attention in the research and development of rotational seismometers due to their advantages of all-solid-state,highly sensitivity and wide frequency response.To enhance the sensitivity of fiber optic rotational seismometers,long fiber loops are commonly employed.However,increasing the length of the optical fiber leads to thermal phase noise and relative intensity noise from the light source within the optical fiber loop,limiting their sensitivity performance.This paper conducts an in-depth analysis on the noises that degrade the sensitivity of fiber optic rotational seismometer.A dual-polarization configuration is proposed using the slow and fast axes of polarization-maintaining fibers,and its optical configuration as well as demodulation algorithm are theoretically analyzed.The results show that the dualpolarization configuration can effectively suppress thermal phase noise and relative intensity noise.On this basis,a three-component dual-polarization fiber optic rotational seismometer DP-Rot3Cis developed,and the static and dynamic tests are conducted.The results show that the sensitivity of the seismometer reaches ■,comparable to the French Bluseis-3A.It exhibits a flat response across a frequency range of 0.01～125 Hz and possesses a nonlinearity of less than 6ppm (1ppm=0.0001%)over a dynamic range of-300to+300°/s.These results demonstrate that DP-Rot3Chas high precision,wide frequency band,large dynamic range and high linearity.DP-Rot3Chas been applied in multiple practical scenarios,including artificial active source observation,high-speed-railway seismology observation,natural earthquake observation,and other fields.The above experiments indicate that DP-Rot3Cprovides a high-precision tool for observing the rotation motion for engineering exploration,seismological research,and other applications.更多还原