  Strain engineering is a powerful tool for tuning physical properties of 2D
materials, including monolayer transition metal dichalcogenides (TMD) -- direct
bandgap semiconductors with strong excitonic response. Here, we demonstrate an
approach for local characterization of strain-induced modification of excitonic
photoluminescence in TMD-based materials. We reversibly stress a monolayer of
MoSe$_2$ with an AFM tip and perform spatio-spectral mapping of the excitonic
photoluminescence in the vicinity of the indentation point. To fully reproduce
the experimental data, we introduce the linear dependence of the exciton energy
and corresponding photoluminescence intensity on the induced strain. Careful
account for the optical resolution allows extracting these quantities with good
agreement with the previous measurements, which involved macroscopic sample
deformation. Our approach is a powerful tool for the study of local
optomechanical properties of 2D direct bandgap semiconductors with strong
excitonic response.
