Believing that the detection of hemoglobin possesses a vital role in the discovery of many diseases, we present in this work a simple method for sensing and detecting hemoglobin based on one-dimensional photonic crystals. Implementing hemoglobin as a defect layer inside the proposed photonic crystal results in a resonant peak evolving within the bandgaps. The strong dependence of these resonant peaks on concentration and the consequent refractive index are the essential bases of the detection process. The role played by these parameters together with the angle of incidence on performance and efficiency of our sensor is demonstrated. In the vicinity of the investigated results, we demonstrate the values of sensitivity, figure of merit (FOM), signal-to-noise ratio (SNR), and resolution to optimize the performance of our sensor. The numerical results show a significant effect of polarization mode on performance of this sensor. For TE polarization with an angle of incidence equal to 45°, we investigated sensitivity of167nmRIU−1, SNR of 0.23, FOM of0.63RIU−1, and resolution of 257 nm.

The sensing of protein is of great importance because of its prominent role in building and repairing tissues. In this work, we present a simple design for the detection and sensing of protein using one-dimensional defective photonic crystals. The main idea of our work is included in the theoretical investigation of the transmittance properties of the resonant mode produced inside the photonic band gap. Our study uses the characteristic matrix method and curve fitting. The main reason for our study is to detect the concentration of a protein solution using an efficient, accurate, and simple method. Here, the defect layer is filled with a protein solution. Our idea depends on two hypotheses, and the first one is based on the appearance of a resonant peak on the photonic band gap. The second one depends on a change in the position of this resonant peak with the concentration of the protein solution. The effect of many parameters on the performance of our sensor, such as the thickness of the defect layer and the sensitivity, is demonstrated. The numerical results could present a simple way to design an accurate, stable, efficient, and low-cost protein sensor compared to other current methods and techniques.

In this paper, we theoretically investigate the effect of an external magnetic field on the properties of photonic band structures in two-dimensional n-doped semiconductor photonic crystals. We used the frequency-dependent plane wave expansion method. The numerical results reveal that the external magnetic field has a significant effect on the permittivity of the semiconductor materials. Therefore, the photonic band structures can be strongly tuned and controlled. The proposed structure is a good candidate for many applications, including filters, switches, and modulators in optoelectronics and microwave devices.