An Improved Optical Biosensor design using defect/metal multilayer photonic crystal for Malaria Diagnosis

An improved design of an optical biosensor using metal/defect/metal multilayer photonic crystal is proposed for malaria diagnosis. The defect layer corresponds to different hemoglobin concentration related to malarial stages. Transfer matrix method is used to estimate transmission, reflection and absorption. To analyse the tunable characteristics, metal layer width, incident angle and defect layer, refractive index has been varied. It is found that defect modes shifting improved further with increase in metal layer thickness and incident angle. Surface Plasmon created at metal defect interface results in a decrease in transmission. For both the polarizations (TE and TM), localized defect mode exhibit blue shift with increase in incident angle. However, the transmission peak is found to decrease with incident angle on TE polarization. The proposed sensor has been found to be of higher sensitivity as 1114 nm/RIU for malaria diagnosis as compared to our earlier works.