The variable optical attenuator (VOA) has attracted extensive attention due to its promising applications in dense wavelengthdivision multiplexed (DWDM) systems. It is used to control the gain of optical amplifiers, thus equalizing the channel powers in add/drop nodes of the systems [1]. It can also dynamically regulate the channel powers regardless of fluctuations in the input light power and polarization. It is expected that an array structure containing multiple attenuators in a single chip is preferable for future DWDM systems applications. One of the most critical issues for the implementation of the array is the electrical power consumption of the unit device involved.