Analysis of the Transmission Spectra of Optical Microcavities Using the Mode Broadening Method

This paper presents an algorithm for processing the transmission spectra of whisperinggallery optical microcavities for use as a nanoparticle detector. The algorithm is based on the broadening of the microcavity resonance curve during precipitation of nanoparticles on the microcavity surface. Experimental results on the detection of particles are compared with Langmuir adsorption theory. The contribution of the instability of the excitation radiation source due to the temperature drift of the resonant frequency to the measurement error is estimated.