Plasmon-induced transparency sensor for detection of minuscule refractive index changes in ultra-low index materials

Deep Learning for Optical Sensor Applications: A Review

Over the past decade, deep learning (DL) has been applied in a large number of optical sensors applications. DL algorithms can improve the accuracy and reduce the noise level in optical sensors. Optical sensors are considered as a promising technology for modern intelligent sensing platforms. These sensors are widely used in process monitoring, quality prediction, pollution, defence, security, and many other applications. However, they suffer major challenges such as the large generated datasets and low processing speeds for these data, including the high cost of these sensors. These challenges can be mitigated by integrating DL systems with optical sensor technologies. This paper presents recent studies integrating DL algorithms with optical sensor applications. This paper also highlights several directions for DL algorithms that promise a considerable impact on use for optical sensor applications. Moreover, this study provides new directions for the future development of related research.

Hybridization of surface plasmons and photonic crystal resonators for high-sensitivity and high-resolution sensing applications

In this paper, an optical refractive index (RI) sensor based on a hybrid plasmonic-photonic crystal (P-PhC) is designed. In the sensor's structure, some metallic rods are embedded in a rod-type photonic crystal (PhC) structure. Numerical simulations are performed based on the finite-difference time-domain (FDTD) method. The obtained results illustrate that the localized surface plasmons (LSP) induced by metallic rods can be excited in a PhC lattice to generate a hybrid P-PhC mode. According to the results, the hybrid mode provides unique opportunities. Using metallic rods in the coupling regions between waveguides and the resonant cavity significantly increases the interaction of the optical field and analyte inside the cavity. The simulation results reveal that high sensitivity of 1672 nm/RIU and an excellent figure of merit (FoM) of 2388 RIU-1 are obtained for the proposed hybrid P-PhC sensor. These values are highest compared to the purely plasmonic and or purely PhC sensors reported in the literature. The proposed sensor could simultaneously enhance sensitivity and FoM values. Therefore, the proposed hybrid P-PhC RI sensor is a more fascinating candidate for high-sensitivity and high-resolution sensing applications at optic communication wavelengths.

Unified model for plasmon-induced transparency with direct and indirect coupling in borophene-integrated metamaterials

We propose, both numerically and theoretically, a uniform model to investigate the plasmonically induced transparency effect in plasmonic metamaterial consisting of dual-layer spatially separated borophene nanoribbons array. The dynamic transfer properties of light between two borophene resonators can be effectively described by the proposed model, with which we can distinguish and connect the direct and indirect coupling schemes in the metamaterial system. By adjusting the electron density and separation of two borophene ribbons, the proposed metamaterials enable a narrow band in the near-infrared region to reach high transmission. It provides a new, to the best of our knowledge, platform for optoelectronic integrated high-performance devices in the communication band.