Numerical modeling of improvement in slope sensitivity of InGaN-based ring laser rotation sensor

摘要

The slope sensitivity of an active ring laser gyro can be improved by decreasing the group index and the wavelength without having to increase the size of the ring. The nonlinear interaction between a strong driving wave and a probe wave (which is in the spectral vicinity of the driving wave) results in modification of group index of the probe wave. The reduced group index can be used to improve slope sensitivity (scale factor) of a ring laser gyro. By using an InGaN-based multiple quantum well (MQW) semiconductor laser the sensitivity can be further improved, because the lasing wavelength is shorter and the nonlinear interactions between the modes in this material system are also stronger when compared with GaAs-, InGaAs-, and InGaAsP-based laser systems. The finite element method is used to model a realistic InGaN/GaN quantum well waveguide structure. The induced dispersion is calculated and variation of the group index is obtained by the numerical modeling. The spectral position of the critically anomalous dispersion point is shown in wide range of driving wave intensity.