3-V driven pop-up micromirror for reflecting light toward out-of-plane direction for VOA applications

Novel axial aligned fiber-to-fiber variable optical attenuator (VOA) that used a pop-up micromirror to reflect the attenuated light toward out-of-plane was designed and characterized. Unlike axial-type VOA devices that suffer from large return loss and large operation voltage, U-shaped electrothermal actuator array only requires 3-V dc bias to achieve 37-dB attenuation in our new design. Insertion loss, return loss, and wavelength-dependent loss at attenuation of 3 dB were measured to be 0.3, -45, and 0.28 dB, respectively.