Abstract:Variable optical attenuator (VOA) arrays can be widely applied in optical communication and optoelectronic systems, but few VOA arrays are reported. Here a liquid-stop based microfluidic VOA array is proposed. It uses a spiral orbit to achieve different degrees of synchronous energy attenuation of multiple beams, or uses an annular orbit to achieve a same degree of synchronous energy attenuations, where the clear aperture of liquid stop is regulated by the electrowetting-on-dielectric effect. It has a compact structure, small volume, simple operation and low cost. Meanwhile, the attenuation ratio of beams can be flexibly adjusted to achieve the power equalization. The research results indicate that the VOA array has a wide attenuation range (0-100% attenuation) and very small insertion loss (0.26 dB) over general VOA arrays. The response time is 0.1 ms, and it is insensitive to the polarization. It can also act as an optical switch array. The proposed VOA array demonstrates the potential of integration and high performance, and it can provide a cost-effective way for applications.