WIDELY TUNABLE FABRY-PEROT FILTER USING GA(AL)AS-ALOX DEFORMABLE MIRRORS

A microelectromechanically tunable Fabry-Perot (FP) microinterferomete r is demonstrated using Ga(AI)As-AlOx DBR micromirrors separated by an air gap. The broad-spectral response of Ga(AI)As-AlOx distributed Bra gg reflector (DBR) micromirrors allows 3-dB bandwidth of the cavity to remain narrow and stable over the tuning range, Two devices with diff erent number of mirror structures were demonstrated exhibiting linewid ths of 0.5 and 2.0 nm, tuning ranges of 59 and 83 mn, respectively, In addition to a fundamental FP spatial mode, we also observe higher ord er spatial modes that we associate with a lensing effect caused by par tially oxidized AlGaAs layers within the mirror layers.