Widely tunable Fabry-Perot filter using Ga(Al)As-AlO_x deformable mirrors

Abstract

A microelectromechanically tunable Fabry-Perot (FP) microinterferometer is demonstrated using Ga(Al)As-AlO/sub x/ DBR micromirrors separated by an air gap. The broad-spectral response of Ga(Al)As-AlO/sub x/ distributed Bragg reflector (DBR) micromirrors allows 3-dB bandwidth of the cavity to remain narrow and stable over the tuning range. Two devices with different number of mirror structures were demonstrated exhibiting linewidths of 0.5 and 2.0 nm, tuning ranges of 59 and 83 nm, respectively. In addition to a fundamental FP spatial mode, we also observe higher order spatial modes that we associate with a lensing effect caused by partially oxidized AlGaAs layers within the mirror layers.