Thermal dependence of the signal to noise ratio of self-mixing sensors based on multimode VCSELs

Abstract

We investigate experimentally the signal-to-noise ratio (SNR) of the self-mixing signal from a Vertical-Cavity Surface-Emitting Laser (VCSEL) based sensor as a function of laser driving current and the ambient temperature. The maximum SNR in the current-temperature space can be well approximated by the model related to the temperature dependence of the threshold current for individual VCSEL transverse modes.