The field of cavity-optomechanics is interested in coupling degrees of freedom of a mechanical oscillator to a light field. Recently, this field received considerable attention due to the promise, among others, of observing quantum mechanical effects at the macroscopic scale. A requirement to observe such effects is a large optomechanical coupling, which can be enhanced by putting the mechanical oscillator in an optical cavity with the shortest length possible to increase momentum transfer from photons (more bounces per second). Typically, the position of the mechanical oscillator modulates the resonant frequency of the optical cavity (dispersive coupling), but another interesting (and less studied) case is when the cavity decay rate (i.e., the lifetime of the photons inside it) is modulated by the mechanical oscillator’s position (dissipative coupling). In this talk, I will introduce the field of optomechanics, rapidly overviewing breakthrough experiments and proposals. Then, I will discuss my research project which aims to create an ultra-short cavity enabling dissipative coupling.