Presentation Information
[9a-N302-8]Resonance Mode Engineering in Defect-Coupled Two-Dimensional Photonic Crystal Cavities for Detection of Milk Adulteration
〇(D)Shamshad Alam1, Uttara Biswas1, Mohd. Mansoor Khan2, Ramesh Kumar Sonkar1 (1.IIT Guwahati, 2.IIIT Guwahati)
Keywords:
Optical sensor,Refractive index,Photonics Crystal
Milk is a widely consumed nutritional product, and its quality is strongly influenced by factors such as water content, fat concentration, and processing conditions. In this work, a defect-engineered V-cavity photonic crystal resonator (DEV-PhCR) is proposed for milk quality monitoring through refractive index (RI) sensing. The two-dimensional photonic crystal structure consists of silicon rods arranged in a triangular lattice with a V-shaped defect cavity coupled to line-defect waveguides, enabling strong optical confinement and enhanced light–matter interaction. The structure was analyzed using the finite-difference time-domain (FDTD) method in Ansys Lumerical. Variations in milk density and RI caused by water adulteration (81–90%) produce measurable resonance wavelength shifts in the transmission spectrum. The proposed sensor exhibits a maximum sensitivity of 1200 nm/RIU, a quality factor of 302.51, a figure of merit of 237.62, and a response time of 0.171 ps. Owing to its compact footprint, high sensitivity, and label-free operation, the proposed device shows strong potential for food quality monitoring and integrated photonic sensing applications.