en فیبر نوری، حسگرهای فیبری و مخابرات نوری Optical Fiber, Fiber Sensors, and Optical Communications پژوهشي Research <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-weight:bold">This study introduces a novel analytical model for estimating the effective thermal conductivity of photonic crystal fibers (PCFs) with a honeycomb lattice cladding. This innovative model allows for the estimation of thermal conductivity across layers and the entire honeycomb structure for a wide range of hole diameters and inter-hole spacings, eliminating the need for specialized simulation software. As an analytical model, it offers higher computational accuracy compared to previous methods. Unlike triangular lattices, the modeling process explicitly considers the two distinct unit cell types inherent to the honeycomb lattice.</span></span></span><br> <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-weight:bold">Using the proposed method, we evaluated the thermal conductivity of honeycomb-structured PCFs for various hole sizes and pitches. Results indicate that thermal conductivity stabilizes with an increasing number of layers, and the air filling fraction plays a dominant role in thermal performance, leading to a significant reduction in conductivity. This work enables the rapid optimization of PCFs for high-power laser applications (e.g., Air-Si PCFs) and low-loss sensors (e.g., H₂-ZBLAN PCFs), with direct implications for thermal stability in optical systems.</span></span></span> Thermal Conductivity Coefficient, Honeycomb Structure, Mathematical Model, Thermal Resistance. 151 160 http://ijop.ir/browse.php?a_code=A-10-1009-1&slc_lang=en&sid=1 Maryam Karimi mykarimi@aeoi.org.ir 10031947532846005352 10031947532846005352 Yes Faculty Member of Photonic and Quantum Technology Research School, Nuclear Science and Technology Research Institute, AEOI, Tehran, Iran.