Search

Cancer and its diverse variations pose one of the most significant threats to human health and well-being. One of the most aggressive forms is blood cancer, originating from bone marrow cells and disrupting the production of normal blood cells. The incidence of blood cancer is steadily increasing, driven by both genetic and environmental factors. Therefore, early detection is crucial as it enhances treatment outcomes and improves success rates. However, accurate diagnosis is challenging due to the inherent similarities between normal and cancerous cells. Although various techniques are available for blood cancer identification, high-frequency imaging techniques have recently shown promise, particularly for real-time monitoring. Notably, terahertz (THz) frequencies offer unique advantages for biomedical applications. This research proposes an innovative terahertz metamaterial-based biosensor for high-efficacy blood cancer detection. The proposed structure is ultra-compact and operates across five bands within the range of 0.6 to 1.2 THz. It is constructed using a polyethylene terephthalate (PET) dielectric layer and two aluminum (Al) layers, with the top layer serving as a base for the THz-range resonator. Careful design, architectural arrangement, and optimization of the geometry parameters allow for achieving nearly perfect absorption rates (>95%) across all operating bands. The properties of the proposed sensor are extensively evaluated through full-wave electromagnetic (EM) analysis, which includes assessing the refractive index and the distribution of the electric field at individual working frequencies. The suitability for blood cancer diagnosis has been validated by integrating the sensor into a microwave imaging (MWI) system and conducting comprehensive simulation studies. These studies underscore the device's capability to detect abnormalities, particularly in distinguishing between healthy and cancerous cells. Benchmarking against state-of-the-art biosensors in recent literature indicates that the proposed sensor is highly competitive in terms of major performance indicators while maintaining a compact size. [ABSTRACT FROM AUTHOR]

Graphene‐based absorbers have various modern applications across industries due to their exceptional properties. Some common applications include: thermal management and energy storage. Herein, the design and simulation of a broadband tunable absorber based on graphene with perfect absorption spectra in the near‐infrared region are reported. The proposed structure consists of an MgF2 layer and golden disc surrounded by L‐shaped golden arms placed on single layer of graphene. The structure guarantees polarization‐insensitive (PI) performance under normal incident due to the symmetrical design. The investigation of the PI of the structure reveals almost similar absorption for oblique incident angles up to 55° for TM and up to 60° for TE polarization. The desirable resonance wavelength is achievable by tuning the geometrical parameters. By changing the chemical potential of graphene, the absorption and bandwidth of absorber are controllable. A full width at half maximum of 330 nm is another superiority of this absorber. These considerable aspects of the proposed structure make it practical for varieties of applications such as cloaking, sensing, switching, and so on. [ABSTRACT FROM AUTHOR]

A half-subtractor is a digital circuit that subtracts two inputs and displays the result in two outputs. Photonic crystals (PhCs) are used in optical circuits, including encoders, multiplexers, adders, subtractors, timers, counters, etc. This paper reviews and compares some of the all-optical half-subtractors and full-subtractors based on PhCs reported to date. We study physical parameters, including the arrangement of dielectric rods, rod radius, lattice constant, structure area, background material, and resonator type and illustrate the structure with a small size is suitable for integration in a photonic chip. Another crucial factor is the optical power difference between the two logic states of 0 and 1. A large difference between these two values increases the contrast ratio and reduces the detection error in the output. Delay time as a key parameter specifies that the input signal will leave the desired output after a few femtoseconds. Linear structures have the lowest delay time, fall time, and rise time among compared structures. But on the other hand, non-linear structures have the highest amount of contrast ratio. In the recent papers, relatively favorable delay times are obtained, equal to 0.06, 0.1, and 0.85 ps, respectively. Also, the fall times are a small value and are equal to 0.05, 0.1, and 0.25 ps, respectively, and the rise times are equal to 0.1, 0.5, and 0.7 ps, respectively. Also, the contrast ratio values are high and acceptable which are equal to 25.88, 18.80, and 18.40, respectively. [ABSTRACT FROM AUTHOR]