This papers deals with the study of novel building blocks suitable for architectures of MEMS tunable lasers integrated in SOI platforms. These building blocks are based on the use of 1D photonic crystals (1D PCs) made of silicon-air thin layers stacks. These provide high reflectivity in certain wavelength range as well as access to simple Fabry-Perot cavities. The latter was studied more in detail and simulations are presented along with preliminary experimental results. A tilted Fabry-Perot cavity was analyzed for its potential of mode selector to prevent for mode hopping and thus enable continuous mode tuning by control of separation gap. As 1D PCs exhibit dispersion characteristics, this behavior is analyzed as well for its potential use for compensation purposes of wavelength dependence of the refractive index in the III-V gain medium.