Photonic integration involves integration of several photonic devices on one common platform. It is able to reduce the system size and cost, improve the system reliability, and minimize the optical loss. In the presentation, the design of some building blocks in photonic integration are presented, namely the vertical coupler for polarization manipulation, lateral mode filter and coarse wavelength splitter by using directional coupler. The fabrication processes of photonic devices are also studied and are used in the fabrication of simple photonic integrated device. Room temperature dry etching of InP using chlorine recipes are optimized. The etch rates are reasonable and the sidewall profiles are almost 90º. Integrated devices between vertical coupler and multimode interferometer, and between multimode interferometer and electroabsorption modulator, are fabricated. The fabrication is complicated as it involves multiple layers and passive-active integration, but nevertheless, the devices are fabricated. The optimization of the device performance is beyond the scope of the thesis.