The present article proposes an open-loop dual-core plasmonic optical fiber sensor for dual-parameter detection. For the first time, a graphene-TiO2-gold composite structure was used in an open-loop channel of D-type, and a two-parameter detection was produced using a PDMS-Au temperature sensing channel. The sensing mechanism is based on the surface plasmon resonance (SPR) interaction between the photonic crystal fiber core and the metal layer. The analytical approach is complete vector finite element analysis. The coupling loss, resonant peak, sensitivity, and other performance factors are analyzed. According to analogy and simulation analysis, the sensor has a maximum wavelength sensitivity of 27794.37 nm / RIU when the refractive index of the measured area is 1.31∼1.42, and maximum temperature sensitivity of 10.50 nm /°C in the range of 10 °C to 40 °C.

Two-dimensional (2D) materials, which have attracted attention due to intriguing optical properties, form a promising building block in optical and photonic devices. This paper numerically investigates a tunable and anisotropic perfect absorber in a graphene-black phosphorus (BP) nanoblock array structure. The suggested structure exhibits polarization-dependent anisotropic absorption in the mid-infrared, with maximum absorption of 99.73% for x-polarization and 53.47% for y-polarization, as determined by finite-difference time-domain FDTD analysis. Moreover, geometrical parameters and graphene and BP doping amounts are possibly employed to tailor the absorption spectra of the structures. Hence, our results have the potential in the design of polarization-selective and tunable high-performance devices in the mid-infrared, such as polarizers, modulators, and photodetectors.

Two-dimensional materials, which can be used to modify sensor surfaces to increase sensor sensitivity, have important research in the field of sensors. In this paper, we design a highly sensitive D-shaped photonic crystal fiber sensor with graphene-MoS2 heterostructure for hemoglobin detection. The research utilized the finite element method and involved addition of different layers of graphene and MoS2 to the optical fiber sensing area, and it was determined that the hybrid nano-heterostructures made of monolayer graphene and bilayer MoS2 provided the greatest improvement in sensor performance. The sensor shows excellent detection performance in 1.33∼1.38 refractive index units. Using incident light in the wavelength ranges of 650 nm and 850 nm, the proposed sensor has a maximum wavelength sensitivity of 4700 nm/RIU, a maximum amplitude sensitivity of 327.5 RIU-1, and a resolution of 2.17×10−5 RIU. The range of hemoglobin concentrations detected with this sensor was 0 g/L∼241 g/L, with an average sensitivity of 0.7 nm/(g/L). A fiber biosensor was enhanced with graphene-MoS2 hybrid nanostructures, which exhibit excellent photoelectric properties and detection performance, enabling highly sensitive, highly accurate, and real-time hemoglobin detection. The result shows the significant research value and application prospects in the field of biomedical detection.