Real-time quantitative terahertz microfluidic sensing based on photonic crystal pillar array

The microfluidic sensing based on the photonic crystal (PC) pillar array was investigated in the terahertz (THz) region. We fabricated the silicon PC sensors, and experimentally and theoretically demonstrated their resonances by using the THz time-domain spectroscopy system. According to the corresponding changes of the resonances dependent on the different microfluidics on the PC sensor, the qualitative monitoring can be achieved. By establishing the relation between the experimental data and simulations, the amount of microfluidic at each moment on the different PC sensors can be exactly determined. These PC sensors have great promising potential in the real-time quantitative sensing.