Dataset relating to 'Apertureless near-field terahertz imaging using the self-mixing effect in a quantum cascade laser'

This dataset relates to data presented in the work, 'Apertureless near-field terahertz imaging using the self-mixing effect in a quantum cascade laser'. In this work we report two-dimensional apertureless near-field terahertz (THz) imaging using a quantum cascade laser (QCL) source and scattering probe, and demonstrate a resolution of ~1 μm (~λ/100), which represents the highest value achieved to date with a THz QCL. By employing a detection scheme based on self-mixing interferometry, our approach offers experimental simplicity by removing the need for an external detector, and also provides sensitivity to the phase of the reinjected field. We demonstrate a near-field enhancement of the scattered field amplitude for small probe-sample separations, and investigate how the phase of the reinjected field varies with the round-trip time in the external cavity.