This paper presents a new capsule-shaped sensor to detect the glucose concentration in the human body. The model under study was formulated by relying on the index change in the refractive index (RI) because of the change in the sample that infiltrated the cavity. The index of refraction change is accompanied by modifying the resonant wavelength. The recommended model has considered the simple shape and ease of manufacture, along with other characteristics such as sensitivity and a low detection limit. The results report a high sensitivity of S = 546.72 nm/RI unit (RIU), a high quality factor of Q = 2066.24, a low detection limit of DL = 1.44 × 10⁻⁴ RIU, and a high value of transmission of 97%, which are considered to be sufficient and efficient in detecting measured material. This proposed model provides many opportunities and is promising for the manufacture of different types of sensing detection devices.

We present a novel type of slow-light photonic crystal waveguide prepared by changing only the position of the second rows of holes in the direction of light propagation of a line-defect photonic crystal waveguide. A nearly constant group index is achieved of 30, 31 and 32 over wavelength ranges of 10.4 nm, 13.5 nm and 14.5 nm, respectively. In addition, a large normalized-delay-bandwidth product ranging from 0.201 to 0.300 is obtained at the operation wavelength of 1550 nm.