Plasma cell sensor using photonic crystal cavity.

The performance of one-dimensional photonic crystal for plasma cell application is studied theoretically. The geometry of the structure can detect the change in the refractive index of the plasma cells in a sample that infiltrated through the defect layer. We have obtained a variation on the resonant peak positions using the analyte defect layer with different refractive indices. The defect peak of the optimized structure is red-shifted from 2195 to 2322 nm when the refractive index of the defect layer changes from 1.3246 to 1.3634. This indicates a high sensitivity of the device (S = 3300 nm/RIU) as well as a high Q-factor (Q = 103). The proposed sensor has a great potential for biosensing applications and the detection of convalescent plasma.