激光陀螺原理（Laser gyro principle）.docVIP

激光陀螺原理（Laser gyro principle） laser gyro The principle of laser gyro is to use the optical path difference to measure the angular velocity (Sagnac effect). In the closed optical path, the Two beams of light and light interference transmitted in a clockwise direction and counterclockwise direction are detected by a light source by detecting phase difference or interference bars The change of the pattern can be used to measure the angular velocity of the closed light path. The basic element of laser gyro is ring laser Closed light path optical device is composed of a triangular or square made of quartz, there are one or several with mixed gas (helium neon Tubes, two opaque mirrors and a semi transparent mirror. Excite mixture gas with high frequency power supply or DC power supply, Monochromatic laser. In order to maintain the loop resonance, the circumference of the loop should be an integral multiple of the wavelength of the light wave. The laser is guided by a translucent mirror A laser interferometer that couples two beams in opposite directions through a reflector, through a photodetector and a circuit that is input to output angle ratio Example of digital signals. The main technologies required for laser gyro are drift, noise and blocking threshold. 1. laser gyro drift The drift of laser gyro shows the instability of zero bias, and the main sources of error are the refractive index of resonant light path With anisotropy, the flow of He Ne plasma in the laser tube, the anisotropy of the dielectric diffusion, etc.. Noise of 2. laser gyro The noise of laser gyro is shown in angular velocity measurement. Noise comes mainly from two aspects: first, the spontaneous nature of the laser medium Emission, this is the quantum limit of laser gyro noise. The two is mechanical dither, which is the bias technique adopted by most laser gyros When the dithering motion changes direction, the angular rate of the jitter is low, and in a short time, below the blocking threshold, an i