Ring laser gyroscope

About: Ring laser gyroscope is a research topic. Over the lifetime, 2070 publications have been published within this topic receiving 18609 citations. The topic is also known as: Sagnac interferometer.

The effect of slow fluctuation processes in the ring laser gyroscope on its bias instability

Abstract: We have identified the origin of the bias instability of the laser gyroscope, which included the ring heliumneon laser with mechanical dither. The data observed consist of the gyro counts of vertical projection of the Earth's angular rate and the bilateral gas discharge maintaining voltages in the ring laser. The measurements were carried out under conditions of prolonged operation after the gyroscope was started, stabilization of the discharge currents and the ambient temperature. Detected spontaneous changes in the maintaining voltages are the results of fluctuations in the contamination concentration in the active medium of the laser. The revealed process leads to the non-reciprocity of counter propagating waves, which the ring laser generates. The swing of the trend line for registered angular rate correlates with the oscillations of the bilateral gas discharge maintaining voltages. The Allan variance analysis confirms the observed value of the laser gyro bias instability that makes it possible to identify the process of the appearance of unsteady gas flows in the ring laser with changes in the concentration of contaminations in the laser active medium.

Passive resonance type ring laser gyro

Abstract: PURPOSE:To improve a temperature characteristic and increase a resolving power by constructing a ring resonator having a phase modulator around a cylindrical body composed of a material with a low coefficient of expansion and forming an optical element on a disk-shaped substrate provided on the end of the ring resonator. CONSTITUTION:A ring laser gyro 1 is constituted by a cylindrical body 2 provided with a ring resonator and a disk-shaped substrate 3 provided with an optical element, such as a laser or the like. Both the cylindrical body 2 and substrate 3 are made of a material with a low coefficient of thermal expansion, such as quartz, saphire, ceramics or the like, and united by adhesion. A thin film wave directing path 4 made of quartz glass or the like that constitutes the ring resonator is formed around the outer circumferential surface of the cylindrical body 2. In the approximately middle intermediate position, a phase modulator 5 is provided. Due to such structure, the ring resonator can have a sufficiently large optical path length, a resolving power is high, a temperature characteristic is stable and reliable and the size of the whole apparatus can be reduced.

Study on the technology of the first kind of dispersion equalization for four frequency differential laser gyro

Abstract: The frequency stabilization error is an important error for four frequency differential laser gyro (FFDLG). The first kind of dispersion equalization technology (FKDET) can minimize the frequency stabilization sensitivity of FFDLG essentially. From the independent dual-gyro approximation model, the principle and physical picture of FKDET are analyzed. Basing on the analysis, the calibration algorithm is put forward. At last the experimental system is set up. Experimental results show that the frequency stabilization sensitivity of FFDLG can be reduced more than 300 times by using FKDET. The startup and long term drift are also decreased of 0.00396 and 0.00152 respectively. Under temperature environment between −40 °C ∼ 60 C, the drift difference is reduced at least 0.6 by using FKDET. Therefore, FKDET is helpful to improve the performance of FFDLG for practical engineering application.

Apparatus for laser gyro

Abstract: The present invention discloses an apparatus for laser gyros capable of determining occurring incremental lock-in error by characterizing behavior of the sensor system before and after passing through the lock-in region an occurrence of lock-in error.