Research On Fiber-optic Fabry-Perot Accelerometer

The fiber-optic Fabry-Perot accelerometer is a sensor that calculates the acceleration based on the phase change of the fiber Fabry-Perot cavity.With the advantages of Anti-electromagnetic interference,high sensitivity.Optical fiber sensor is an important sensor widely used in aerospace,defense security,marine exploration,petroleum exploration,transportation,ecological monitoring,etc.At present,the sensor has the disadvantages of high manufacturing process difficulty and high cross-sensitivity.Based on the theoretical simulation of the sensor,we optimizes the sensor's design structure,and proposes a new manufacturing process,produces a highly sensitive and low sensitive acceleration sensor.Using ANSYS finite element software to build the model of Fiber-Optic acceleration sensor.The Fabry-Perot accelerometers with four types of one arm,two arms,four arms,and circle arms are modeled which six parameters caused effects on the change of sensor cavity length,that is thickness and diameter of the sensor structure,the length and width of the cantilever,and the overall periphery of the sensor.It was found that the cavity length increased linearly with the thickness of the sensing structure,the length of the cantilever beam and the peripheral diameter increased exponentially,but the thickness and width index of the cantilever beam decreased.However,when the sensing structure takes a certain value directly,the cavity length is maximum.In the single-arm configuration,the acceleration sensor has the highest sensitivity.The cross-sensitivities of the four accelerometers were studied.It was found that the accelerometer with single-arm structure has the highest cross-sensitivity in the direction,and the cross-arm sensitivity in the cross-arm structure is the lowest.As the number of sensor cantilever beams increases,the sensitivity gradually decreases,and the direction-crossing sensitivity also decreases.The sensor's acceleration sensitivity is 0.73 rad/g,which measuring range is-8g~8g,the minimum detection acceleration value is 1.37 mg.