A novel spectroscopic optical sensor is presented for cancerous cell detection in various parts of the human body (i.e., cervix, adrenal gland, breast, skin, and blood). An optimized structure based on compact cladding is successfully designed with enhanced sensitivity and very low confinement loss. The parameters like effective area (Aeff), V-parameter (Veff), spot size (Weff), numerical aperture (NA), and beam quality factor are investigated over the wavelength region 1.4–2.5 µm. The consummation of relative sensitivity is also calculated and is superior to other previous work. The numerical investigation indicates that cancerous cells have higher sensitivity than normal cells. The values investigated for the sensitivity of cervical cancer, adrenal gland cancer, skin cancer, blood cancer, and breast cancer of type I and type II are 94.96%, 95.15%, 94.13%, 94.84%, 95.40%, and 95.51% in X-polarization, respectively, which are higher than the calculated values from any prior works. The explored structure is monomode PCF, with silica as a dielectric material. The finite element method (FEM) has been implemented for investigating the numerical values, implemented on COMSOL Multiphysics (version 5.3). The simple design ensures easy fabrication with ongoing techniques.
