Optical techniques are finding more and more use in the domain of nanoelectromechanical systems (NEMS). In particular, Michelson interferometry and Fabry-Perot interferometry have been employed to transduce high frequency motion of NEMS resonators. Here, we review our recent accomplishments in optical probing of NEMS. We discuss
the effectiveness of the above-mentioned optical techniques as the relevant NEMS dimensions are reduced beyond the optical probing wavelength.