Self-referenced refractive index sensor based on double-dips method with bimetal-dielectric and double-groove grating.

Self-referenced refractive index sensors allow more accurate measurements and reduce the influence of extraneous factors. This work proposed a high-sensitivity, self-referenced surface plasmon resonance sensor with Na grating and Au-ZnS composite grating. When Transverse Magnetic-polarized light is incident into the prism, three surface plasmon resonances are excited at the interface of Na-MgF2 grating and Au-ZnS grating. The first one is treated as the reference angle, the second and third are forward and backward surface plasmon resonance, respectively. Using the angular modulation, the single-dip sensitivities are 329.41 deg/RIU and 788.24 deg/RIU in the range of 1.330-1.347. To further improve the performance of the sensor, the double-dips method is adopted, and the average sensitivity in the range of 1.330-1.347 is 1117.65 deg/RIU, while the maximum reaches 4390 deg/RIU. Due to high sensitivity, a good figure of merit can be obtained even with a larger full width at half maximum of 3.30°. This proposed sensor provides potential application in the research of biomolecular detection and chemical testing.

Metamaterial Reverse Multiple Prediction Method Based on Deep Learning.

Metamaterials and their related research have had a profound impact on many fields, including optics, but designing metamaterial structures on demand is still a challenging task. In recent years, deep learning has been widely used to guide the design of metamaterials, and has achieved outstanding performance. In this work, a metamaterial structure reverse multiple prediction method based on semisupervised learning was proposed, named the partially Conditional Generative Adversarial Network (pCGAN). It could reversely predict multiple sets of metamaterial structures that can meet the needs by inputting the required target spectrum. This model could reach a mean average error (MAE) of 0.03 and showed good generality. Compared with the previous metamaterial design methods, this method could realize reverse design and multiple design at the same time, which opens up a new method for the design of new metamaterials.