Abstract
Early detection of oral cancer is crucial for improving patient survival, yet conventional diagnostic techniques remain slow and heavily dependent on chemical reagents. To overcome these limitations, this work proposes a high-sensitivity fiber-optic biosensor illuminated by an Airy-Bessel beam for reliable identification of oral cancerous cells. The sensor is constructed using a cladding-removed multimode fiber, allowing the surrounding analyte to act as the cladding region. This design increases the overlap between the guided light and the analyte, thereby strengthening the evanescent-wave interaction. The use of an Airy-Bessel beam further enhances sensing performance by combining the self-bending characteristics of Airy beams with the non-diffracting nature of Bessel beams, resulting in improved field confinement and coupling efficiency. The sensing mechanism operates on multimodal interference (MMI), where changes in transmitted power reflect the refractive index (RI) contrast between INOK normal cells and YD-10B oral cancer cells. The propagation behavior and sensing response were analyzed using the Beam Propagation Method (BPM) in OptiBPM (v13.1.3). Our Simulations confirm that a 25 cm sensing length achieves a sensitivity of 322.45 dB/RIU, providing a 3.29 -fold improvement compared to Gaussian-beam excitation. With its compact structure, low cost, and fabrication-friendly design, the proposed sensor shows strong potential for early oral cancer detection and broader biomedical sensing applications.