Research Of Optical Gyroscope Based On Slow-light Effect

With the approach of the social information and the improved requirements of communication,it has presented higher requirements for the bandwidth and capacity in the communication networks.In order to solve the problem of electronic bottleneck,in future all-optical network,the electronic exchange will be replaced by all optical switching.Micro-ring resonator is as a fundament devices of all-optical network sensing technology,there is a wide range of applications in information technology,one of the important application is used to manufacture the micro-ring resonator optical gyroscope,micro-ring resonator optical gyroscope can realize a detection of angular velocity in optical field,it is the key component in marine,aviation,aerospace and oil exploration systems and so on.Because the inertial grade of conventional precision interferometric optical gyro greatly restricts the development of sensor technology,to improve the sensitivity of optical gyro,the optical gyroscope based on the phase modulation has also stimulated the extensive study.Although optical gyro sensitivity can be improved by phase modulation,it does not solve the bottleneck.Then the discovery of the slow-light effect in the micro-ring resonator solves this problem and makes the micro-ring resonator gyroscope attract people's attention in recent years.Thus micro-optic gyroscope based on slow-light effect in coupled-resonator has become a hot research.So in this paper,the optical gyroscope based on the phase modulation and the micro-optic gyroscope based on slow-light effect in coupled-resonator are studied,the main research works and results are as follows:Firstly,the structure of nonlinear optical coupler is briefly introduced,and by using the coupled-mode theory,one obtains its transmission matrix.One also has introduced the operating principle of microring resonator,and based on the coupling principle of coupler,one does some analyses on single-coupler,double-couplers microring resonator and cascade micro-ring resonator,respectively.And one describes the structure of the electro-optic modulator,and analysis of the principle of electro-optic crystal as phase modulation.Secondly,a beam of light is launched in splitters and divided into two equal signals,couplers utilizing phase modulation effects,as well as the Sagnac effect generated by two beams of light signal in micro ring,and the sensitivity characteristics of optical gyros are studied.The curve of the final output signal power and rotational speed is obtained by simulation,and compared to that without phase modulation.The results pointed out: the optical gyro based on modulation works in linear region,is easy to measure angular velocity,and better able to determine the direction of rotation.In addition,one also compares optical gyro sensitivity curve in the case of different coupling coefficients,studies show that,at a certain point,fiber-optic gyro sensitivity fiber couplercoupling coefficient is maximized.Thus,one improves the sensitivity of fiber-optic gyroscope by phase modulation,and also can change the coupling coefficient of the optical fiber coupler to achieve it.Thirdly,the micro-optic gyroscope based on slow-light effect in coupled-resonator is mainly studied.Utilizing the Sagnac effect that generates in a rotating closed loop by the optical signal propagating,the phase shift of signal in a single micro-resonator and cascading micro-ring resonator are deduced.Consider the combination of slow light effect and Sagnac effect,transfer matrix and final output are obtained.To study the characteristics of slow light effect,one simulates,at different wavelengths,the changing curve of amplitude the phase of signal and time delay caused by slow light effect.The results show that the time delay and phase transitions,at the resonance wavelength point,occurred.At the same time,in order to study the optical gyro sensitivity,one simulates the curve of optical gyro sensitivity with the change of the rotational angular velocity.Research shows that the use of micro-ring cascade structure achieves in improving the optical gyro sensitivity.And changing the different parameters to simulate the curve of optical gyro sensitivity,the study has shown that the optical gyro sensitivity increases with an increase of radius,with an increase of microring coupling coefficient.Lastly,one studies the impact nonlinear effects on the sensitivity of optical gyro based on double-couplers microring resonator.The signals are modulated by using two coupled micro ring structure,thereby increasing the optical gyro sensitivity.And one compares the sensitivity of the impact of nonlinear effects in the case of micro ring made of two materials,silicon and silicon dioxide.The results showed that,for the silica material,the impact of nonlinear effect can be negligible,and the nonlinear effect of silicon material can cause the optical gyro sensitivity decreases.