The first objective was achieved smoothly as planned. We successfully fabricated optomechanical crystals with optical modes at the target wavelength and quality factors exceeding 105, and mechanical modes around 5 GHz with a linewidth of 10 kHz at low temperatures. During the pursuit of the second objective, we adjusted our initial plan and chose to use rare-earth ions embedded in solids as the atomic system. Specifically, we embedded erbium ions into two host materials: lithium niobate and silicon. We studied the basic properties of erbium ions in these materials and confirmed their suitability for further investigation. Finally, we combined these two systems and achieved the third objective by demonstrating their optical coupling. We addressed the Purcell-enhanced emission of single erbium ions and demonstrated their Stark tuning. Furthermore, we used a gas tuning technique to match the erbium frequency with the optical mode when embedding them in silicon, laying a solid foundation for future steps towards realizing a three-body hybrid system.