Fabrication and Analysis of a MEMS NIR Fabry–Pérot Interferometer

We report the design and fabrication of a tunable MEMS Fabry-Pérot étalon for use in microscale spectroscopic applications. The reflective elements of the interferometer are dielectric mirror stacks optimized for 1500-nm light and the tunability arises via capacitive attraction of a translatable mirror on a spring. The mirror reflectivity was measured to be 97.3%, corresponding to a calculated finesse of 115, while the measured linewidth and FSR are 70 cm
^-1
and 334 cm
^-1
, respectively, corresponding to a measured finesse of 5.