In this paper, we developed Lab On Fiber (LOF) accelerometers based on micro-opto-mechanical cavities on the optical fiber tip. We designed the mechanical structures with different performances features specialized for target applications. In particular, a LOF accelerometer was designed for seismic surveillance applications. The sensor response was first characterized in laboratory, exhibiting a resolution down to 0.44μg/√Hz over a 3 dB frequency band of 60 Hz. To demonstrate the sensor capability to operate in a realistic seismic surveillance system, the developed sensors were continuously used in combination with a commercial seismic sensing network. During the field trial, the LOF sensor registered the ground acceleration associated with the seismic sequence that struck central Italy on October 30, 2016. Overall, the comparison, with traditional sensors incorporated into the geophysical network, demonstrated that the LOF sensors exhibit competitive performance with commercial seismic accelerometers. Ongoing activities are devoted to the design and realization of LOF accelerometers, based either on cantilever structures or on membranes, featuring different mechanical features and thus leading to different performances of the final accelerometer, by retaining the same principle of operation.