Adaptive etalon suppression technique for long‐term stability improvement in high index contrast waveguide‐based laser absorption spectrometers

The authors present an adaptive algorithm based on a non-linear regression model for mitigating time-varying etalon drifts in line-scanned optical absorption spectrometers. By dynamically varying the etalon spectral background using physically realistic degrees of freedom, the authors’ dynamic etalon fitting-routine (DEF-R) significantly increases the spectral baseline recalibration interval as compared to conventional fringe subtraction models....