Vol. 7, Issue 2, Part C (2025)

This investigation presents a comprehensive design methodology for temperature-insensitive polarization-maintaining photonic crystal fibers through strategic integration of polydimethylsiloxane (PDMS) into elliptical air hole structures. Numerical simulations employing the finite-difference time-domain method demonstrate that selective PDMS infiltration enables precise control over thermal sensitivity while maintaining essential optical characteristics. The optimal configuration with   PDMS filling achieves remarkable temperature insensitivity with birefringence variation below 0.5×10⁻⁶ K⁻¹ across the operational range from −20^◦C to 80^◦C. Concurrently, this design maintains practical confinement loss below 0.1 dB/m, flattened chromatic dispersion within ±2 ps /(nm·km) across the telecommunication band, and beat lengths between 1.2-2.1 mm ensuring robust polarization maintenance. Systematic analysis of structural parameters reveals that elliptical hole geometry with   provides optimal birefringence-loss trade-off, while partial PDMS infiltration creates thermo-optic compensation between silica and polymer materials. The figure of merit analysis confirms that   infiltration yields the optimal balance between temperature sensitivity and optical performance. This research establishes a viable pathway for developing stable fiber-optic sensors capable of reliable operation in thermally fluctuating environments, with significant implications for interferometric sensing, structural health monitoring, and precision measurement applications.