  In this paper, a closed-loop micro-opto-electro-mechanical system (MOEMS)
accelerometer based on the Fabry-P\'erot (FP) interferometer is presented. The
FP cavity is formed between the end of a cleaved single-mode optical fiber and
the cross-section of a proof mass (PM) which is suspended by four U-shaped
springs. The applied acceleration tends to move the PM in the opposite
direction. The arrays of fixed and movable comb fingers produce an
electrostatic force which keeps the PM in its resting position. The voltage
that can provide this electrostatic force is considered as the output of the
sensor. Using a closed-loop detection method it is possible to increase the
measurement range without losing the resolution. The proposed sensor is
fabricated on a silicon-on-insulator wafer using the bulk micromachining
method. The results of the sensor characterization show that the accelerometer
has a linear response in the range of 5 g. In the closed-loop mode, the
sensitivity and bias instability of the sensor are 1.16 V/g and 40 g,
respectively.
