Numerical investigation of the influence of a nonlinear absorber on the sensitivity of intracavity laser spectroscopy

It is shown, by numerical modeling in combination with experimental data, that the use of a nonlinear absorber as a spectral contrast enhancer can ensure a real increase in the sensitivity of the method of intracavity laser spectroscopy in the microsecond range by one or two orders of magnitude, without increasing the duration of lasing. Further optimization of all the experimental parameters (using a stronger focusing system, lowering the intrinsic resonator losses, raising the optical density of a nonlinear filter) should increase the sensitivity to weak absorption by three or four orders of magnitude relative to that obtained using normal intracavity measurements.