Design and fabrication of independent-cavity FP tunable filter

This paper presents a novel micro-electromechanical systems (MEMS) FP tunable filter with a FP cavity independent of electro-static actuator, which is fabricated by the bulk micromachining processes. The electro-static actuator based on the parallel-plate capacitive actuation is separated with the FP cavity, and it can be designed without the limits to fabricate the FP cavity. The compatible MEMS fabrication processes with micromirror and FP cavity is proposed, in which the optical micromirror is fabricated with an average surface roughness (Ra) less than 6 nm. The experimental results show that the fabricated FP tunable filter can be tuned 40 nm with a driving voltage from 0 V to 15 V, its 3 dB bandwidth is 0.4 nm and the single mode fiber coupling loss is less than −3.7 dB.