Nonlinear PCFs (HNL-PCFs) can be used in nonlinear-optics applications such as optical parametric amplification, super continuum generation, soliton production, and wavelength converters. The main difficulty in designing highly nonlinear PCFs is determining the zero dispersion wavelength around the telecom window because a PCF with a short pitch and uniformly smaller air-hole dimensions tends to shift the zero-dispersion wavelength towards shorter wavelengths , and a PCF with a higher air-hole dimension relative to the pitch limits the single mode operation bandwidth .The primary goal is study for the photonic crystal fibers to create a simple, high-sensitivity SPR biosensor for multi-analyte detection, with the following specific goals in mind:1.Using plasmonic material2.To include a modern structure3.To alter the RI of an analyte4. Modify the diameter and pitch of the air holes.5. To establish the sensor's linearity and figure of merit PCF is utilised for a variety of modern applications important purposes, including optical fibre communication.