A new design for an optomechanical accelerometer is presented. The design includes a hemispherical optical cavity that can achieve high finesse and a proof mass that is well-constrained by silicon nitride beams. Based on previous work and analysis, the resolution of the accelerometer will be below 1 µg/rt-Hz. Novel MEMS fabrication processes have been developed for the accelerometer that provide optimized optical and mechanical elements. The optical cavity in the accelerometer has been characterized and a tunable laser has been locked to the cavity, thereby demonstrating the possibility for closed-loop operation of the accelerometer.