  A novel wavelength modulation spectroscopy (WMS) laser tuning parameters and
concentration retrieval technique based on the variable-radius-search
artificial bee colony(VRS-ABC) algorithm is proposed. The technique imitates
the foraging behavior of bees to achieve the retrieval of gas concentration and
laser tuning parameters in a calibration-free WMS system. To address the
problem that the basic artificial bee colony(ABC) algorithm tends to converge
prematurely, we improve the search method of the scout bee. In contrast to
prior concentration retrieval methods that utilized the Levenberg-Marquardt
algorithm, the current technique exhibits a reduced dependence on the
pre-characterization of laser parameters, leading to heightened precision and
reliability in concentration retrieval. We validated the simulation with the
VRS-ABC-based technique and the LM-based technique for the target gas C2H2. The
simulation results show that the VRS-ABC-based technique performs better in
terms of convergence speed and fitting accuracy, especially in the
multi-parameter model without exact characterization.
