We present the design and fabrication of active and passive two-dimensional photonic crystal (2D-PC) devices based on GaAs/AlGaAs slab waveguide nano-resonators. The active device is a vertical microcavity exploiting a 2D-PC of air holes arranged in a circular lattice configuration in a GaAs/AlGaAs slab waveguide. The active medium embedded in the waveguide is composed of InAs/GaAs quantum dots emitting around 1300 nm. The investigated passive device is a dual wavelength division splitter exploiting 2D-PC resonators. The spectral response of the active circular microcavity and the transmission characteristics at the different ports of the dual wavelength splitter have been evaluated by a finite-difference time-domain method based computer code. A detailed description of the nanotechnology processes necessary for the fabrication of both active and passive 2D-PC devices is also reported.