Mohammad Ashraful Haque

This paper introduces a nanoscale plasmonic sensor with dual-function capabilities for detecting both pressure and flow rate, designed using a metal-insulator-metal (MIM) bus waveguide coupled with a resonator featuring a horizontal slot and multiple stubs. The sensor demonstrates high pressure sensitivity, achieving 1100.70 nm/MPa for pressure detection, with a Figure of Merit (FOM) of 4.6054, and effectively measures flow rates from 58.544 pL/s to 356.43 pL/s using an optical spectrum analyzer (OSA). Finite Element Method (FEM) simulations were employed to analyze the pressure-induced wavelength shifts, enhancing the sensor’s versatility in integrated sensing applications. The sensor’s compact footprint, simplicity, and ease of fabrication make it ideal for integration into lab-on-a-chip devices. Its dual functionality provides a novel solution for precise, real-time monitoring in biomedical and microfluidic engineering applications.

Plasmonic logic gates are important components in integrated photonics. They are essential for high-speed Boolean computations and data transmission. For this purpose, an all-optical ultra-compact plasmonic logic gate is proposed in this paper. The design uses the metal–insulator–metal (MIM) configuration and the propagation of surface plasmon polaritons. The structure comprises three rectangular input slots coupled to the output slot through a rectangular resonator positioned on a gold (Au) surface with a footprint of 1000nm×800nm. The logic gate is numerically investigated using finite element method analysis. It has been demonstrated that the proposed design can operate as OR, XOR, NOT, and AND gates, and their transmission spectra for different input states are analyzed. This novel solution, to the best of our knowledge, excels in high contrast ratio values of 45.34 dB (OR), 18.29 dB (XOR), 18.29 dB (NOT), and 7.26 dB (AND). The resonant wavelengths of the logic gate are 821.21 nm (OR), 863.23 nm (XOR), 814.71 (NOT), and 787.69 nm (AND). The introduction of Au in this device significantly enhances its plasmonic properties, offering efficient light confinement, chemical stability, and a strong plasmonic response. This plasmonic logic gate not only expands the repertoire of integrated photonics components but also promises breakthroughs in high-speed data processing and communication technologies, positioning it as a crucial advancement in the field of nanophotonics.

This article presents a novel transition metal nitride (TMN)–based plasmonic pressure sensor (PPS) that utilizes a TMN-Insulator-TMN structure. Our proposed sensor is built with Zirconium Nitride (ZrN), an alternative plasmonic material that provides several benefits over conventional plasmonic metals like silver and gold. Notably, ZrN is compatible with standard Complementary Metal Oxide Semiconductor (CMOS) technology and it offers tunability of optical properties. The sensor demonstrates a maximum pressure sensitivity of 177.56 nm/MPa with a resolution of 5.63 × 10 ^-6 MPa. Furthermore, the incorporation of TMN endows the PPS with several beneficial characteristics, such as exceptional hardness, high-temperature thermal stability, optical tunability, and lower electrical resistivity which are typically absent in conventional plasmonic noble metals, limiting their practical application in plasmonic devices. Consequently, our proposed configuration outperforms the conventional noble material-based Metal-Insulator-Metal (MIM) configuration, which removes the barriers to wide-scale adaptations of plasmonic devices by paving the way for the research and development of efficient, robust, and long-lasting sensors at subwavelength scales, thereby forging a link between nanoelectronics and plasmonics.

In this article, we present an innovative plasmonic lab-on-chip (LoC) sensor featuring three ports, utilizing a 1 × 2 demultiplexer to detect two separate samples without cross-contamination. The performance of the sensor is numerically investigated using the finite element method, yielding a maximum sensitivity of 865.9 nm per refractive index unit (RIU) and a figure of merit (FOM) of 58.4 in the 700-920 nm range. The proposed metal–insulator–metal (MIM) structure, incorporating a diamond-shaped silicon nanodot array with a perimeter of less than 100 nm, serves as a sensing surface, detecting changes in the refractive index (RI) of the surrounding medium. Our suggested sensor demonstrates an extraordinary transmission coefficient of around -18 dB, it surpasses classical optics predictions, and its nanoscale light confinement enhances interaction with analytes. Our LoC sensor, based on the MIM structure, achieves high accuracy and precision in measuring small RI changes, making it portable and suitable for on-site applications, and settings with limited resources. This sensor streamlines medical processes by rapidly detecting blood groups and diabetes levels with minimal sample volume, potentially improving patient care efficiency.