Abstract : 3D control of light can be realized, at the wavelength scale, in photonic integrated circuits. The building block used in this study is the photonic crystal slab, which enables an in-plane as well as out-of-plane control of light, thanks to its peculiar dispersion properties. Especially at the gamma point of the dispersion curve, slow Bloch modes can be used to realize vertical emitting devices. In this study, we focus on photonic crystals based on micropillar lattices, as an alternative to classical hole lattices. Besides, micropillar lattices can be seen as a new platform for sensing applications and microfluidic circuits. Indeed, fluids can flow through the micropillar. First, we will describe some devices which operate at Gamma point. We will show that, for the first time, the use of highly resonant Bloch modes allow the experimental demonstration of vertical emitting microlasers. Weakly resonant Bloch modes can be used to realize photonic crystal mirrors and Fabry-Perot microcavities constituted only by photonic crystal mirrors. High quality factors (>10000) obtained in such microcavities allow the fabrication of a new type of VCSEL. In a second part, we will focus on the communication between the photonic crystal devices and the surroundings. First, we will explain how the far field pattern can be optimized. At last, we will study the coupling between a photonic crystal structure and a silicon strip waveguide. We show that simulation results give high coupling efficiency (>90%). The samples, fabricated at the LETI-CEA (Grenoble), are still under process.