Quantum hybrid mechanical systems investigate the interactions between a quantum degree of freedom (a qubit) and macroscopic mechanical motion. The main idea behind this concept is to create an interface between the quantum and the classical domains, with the general perspective to experimentally extend quantum foundational principles at the macroscopic scale. Since its emergence 20 years ago, quantum hybrid optomechanical science has witnessed remarkable progress, in the microwave regime. Concurrently, only a few approaches have successfully addressed hybrid mechanical coupling in the optical domain yet with coupling strengths remaining far below the conditions for coherent quantum-mechanical interaction. This is mainly because of the very short lifetime of the optical emitters used so far, imposing coupling rates which presently appear out of reach. Our project tackles this very issue, by relying on the unique coherence properties of the strain-induced optomechanical coupling in rare-earth ion doped crystals (see Fig. 1(a – b)). With optical decoherence rates in the kHz range, we notably expect strain coupling to operate deep into the strong coupling regime, provided large enough zero-point motion levels, which we will achieve by engineering micro and nanomechanical structures.