We explore the coupling of coherent light (laser radiation) with the motion of mechanical objects. Usually, these investigations take place in optical resonators (cavities). In addition to macroscopic couplings such as radiation pressure, we also investigate micro- and nanoscopic effects, particularly the interaction of the optical near field with micro- and nanostructured surfaces (so-called metamirrors). The coupling of thermal noise (Brownian motion) to the coherent light field is the limiting factor for many high-precision applications such as gravitational wave detectors and optical atomic clocks. By studying the coupling mechanisms and developing specialized metamirrors, it is possible to reduce this noise by several orders of magnitude.