Research Of Integrated Optical Chip For Re-FOG

As an inertial navigation equipment,fiber optical gyroscope(FOG)is widely used in aerospace,ships,submarines,missiles and other fields.As a development direction of FOG,the re-entrant fiber optical gyroscope(Re-FOG)has great research value.Because it has high fiber coil utilization.At present,a new type of Re-FOG is proposed.The integrated optical waveguide modulator is the core device of the scheme.It has integrated a Y-branch modulator and two directional coupler optical switches.It is made from lithium niobate crystal.The main work in this thesis is to analyze,design,manufacture and test this device.Lithium niobate optical waveguide is the basis of integrated optical waveguide modulator.The single-mode transmission condition is deduced by the effective refractive index method in the first part of this thesis.Then the Y Branch modulator and directional coupler optical switch are simulated by Opti-BPM software.Through the simulation,the design of this device is completed.Then,the mask of this device is made according to the designed parameters.The fabrication of the device is completed through the proton exchange process.In the development process,several measures are proposed according to the characteristics of this device.The test work of this device is shown at the end of this thesis.The lithium niobate chip of this device has a length of 44 mm.The width of the waveguide is 6.0 ?m.The insertion loss of this device is 33 dB.The polarization extinction ratio of this device is 42 dB.The Y-branch modulator's half-wave voltage is 11 V.The switching voltages of the two optical switches are 6 V and 7 V,respectively.The channel extinction ratios are 6 dB,12 dB,7 dB,12 dB from the four corresponding output ports.The bandwidths of the two optical switches are 7 MHz and 8 MHz,respectively.The corresponding switching times are 23 ns and 20 ns,respectively.The device made in this thesis is fully realized the design function,and basically meets the given requirements.It can be used to verify the Re-FOG system performance.The development of this device has positive meaning for the research of the Re-FOG.