基于LNOI的环形谐振腔压力传感器

Ring Resonator Pressure Sensor Based on LNOI

环形谐振腔可用于高精度高灵敏度传感,将环形谐振腔与悬臂梁式压力传感器相结合,推导了该压力传感器的灵敏度的表达式,灵敏度会随着所施加压强的不同而变化,当施加的压强为1 kPa时,灵敏度为71.73 pm/kPa。采用低损耗的绝缘体上铌酸锂(LNOI)来设计环形谐振腔,极大地提高了压力传感器的Q值,可提高测得压力的精度。深入分析了临界耦合与非临界耦合、波导损耗、环形波导周长对Q值的影响,并借助Matlab对其进行了分析。结果表明:对Q值影响最大的是波导损耗;环形波导周长增加不会直接增大Q值,但会降低损耗,从而间接增大Q值。计算结果表明,当环形波导半径为80μm,损耗为0.6322 m^(-1)时,Q值高达5.7×10^(6)。

The ring resonator can be used for high precision and high sensitivity sensing.In this paper,the ring resonator is combined with cantilever pressure sensor.The expression of sensitivity of this pressure sensor is derived,the sensitivity will vary with the applied pressure.When the pressure is 1 kPa,the sensitivity is 71.73 pm/kPa.Lithium niobate on insulator(LNOI)which has low loss is used to design ring resonator to obtain a pressure sensor with high Q.It can improve the accuracy of pressure measurement.The effects of critical coupling and non critical coupling,waveguide loss and the perimeter of the ring waveguide on Q factor are discussed and analysed by Matlab.The results show that the most important factor is the waveguide loss.The increasing of the perimeter of the ring waveguide will not increase the Q factor directly,but will reduce the loss and increase the Q factor indirectly.The results show that when the radius of the ring waveguide is 80μm and the waveguide loss is 0.6322 m^(−1),Q factor can reach 5.7×10^(6).