By integrating photonic devices on a silicon wafer containing etched waveguides it is possible to create a complete optical system-on-chip. Such a device can contain all the elements required for implementing a wide range of interferometry techniques including wavelength scanning and phase shifting. In this paper we introduce a hybrid photonics based sensor for surface metrology applications containing the following 'on-chip' components: tunable laser, phase-shifter, wavelength de-multiplexer, and wavelength encoder. This paper presents the design of the system-on-chip as a miniaturised sensor. Initial experimental results are shown which prove the potential of this device as a viable surface measurement tool.