A scheme for variable optofluidic attenuator: Design and simulation

A novel scheme for variable optofluidic attenuator is proposed, by using the multi-bend waveguide structure, and combining with microfluidic channel filled with fluid mixture. The optical performance of our proposed device is numerically investigated by the beam propagation method. The results show that not only large dynamic range and low optical loss for both TE and TM mode input can be achieved, but the dependence of wavelength and polarization is weak in our configuration. Moreover, the proposed optical attenuator has large fabrication tolerance. The proposed device provides an effective means of manipulating optical attenuation, which is useful for applications in the photonic integrated system and optical microfluidic system.