Abstract The properties of PCF have been emerged as an interesting field of research for sensing and detection of wavelengths of different refractive indices. These properties indicate that if analyte is used or not in the core of the PCF that does not influence on the sensor sensitivity. By reshaping the airhole’s size, wavelength sensitivity can be improved. The vast detection limit of refractive indices (RI) is taken 1.33–1.41. In addition, high amount of linearity is obtained at the limit of 1.33–1.42. After simulation, it is obtained that this work proposes high sensitivity of 4250 and 6200 nm/RIU for x and y polarization modes. Because of high sensing capability in the range of various frequencies, this PCF can be applicable for other simultaneous wavelength detection. This PCF also offers its eligibility on the field of biomedical technologies.