A novel quasi-fiber sensor is introduced for alcohol sensing applications with efficient optical guiding properties. The Finite Element Method (FEM) has been employed to explore the guiding properties over a wide range of 0.80 μm–2.8 μm wavelength. The integral purported sensor structure is implemented with scattering boundary condition (SBC) on its outer boundary. The numerical investigation of the optimum structure reveals its relative sensitivity as 60%~98% corresponding to the power fractional distribution of 75% and 72% respectively. Furthermore, a high Numerical Aperture (NA) of 0.68 is obtained from the introduced sensor at the operating wavelength of 2.6 μm. The overall results promise for better performances of proposing sensor, particularly in medical imaging applications.