Reflective Polarization Rotator Design and Investigation in Silicon Waveguide: Comprehensive Insights and Graphical Analysis
Dinesh Kandel
Mid-West University,
Graduate School of Engineering
Email: dinesh.kandel@mu.edu.np
Ram Chandra Pageni
Tribhuvan University , Department of Physics, Patan Multiple Campus.
email: ram.pangeni@pmc.tu.edu.np
Abstract
This research investigates the design and performance of a reflective polarization rotator (PRR) within a silicon waveguide, utilizing a strategic arrangement of rectangular air holes to induce birefringence. The etched air holes enhance the waveguide’s polarization control capabilities, while the non-etched waveguide retains isotropic properties. Through band structure analysis and FullWAVE simulations, high reflection peaks emerge in the reflection spectra, attributed to the photonic bandgap. Performance metrics, including extinction ratio (>20 dB), insertion loss (<0.8 dB), and broadband operation (~350 nm), highlight the device’s potential. This study provides detailed insights into the PRR’s design process and its applications in photonics, supported by graphical and tabular data.The reflective polarization rotator (PRR) presented in this study demonstrates a novel approach to polarization manipulation by leveraging the anisotropic properties introduced through periodic rectangular air holes in a silicon waveguide. These air holes create a birefringent environment that selectively reflects one polarization state while allowing the orthogonal state to propagate, effectively rotating the polarization upon reflection. The contrast between the patterned and unpatterned regions enables precise control over the polarization behavior, which is critical for integrated photonic circuits where compact and efficient polarization management is essential.
The study employs both theoretical and simulation-based analyses to validate the PRR’s performance. Band structure analysis confirms the presence of a photonic bandgap, which is responsible for the observed high reflection peaks in the reflection spectra. FullWAVE simulations further quantify the device’s efficiency, revealing an extinction ratio exceeding 20 dB and an insertion loss below 0.8 dB, indicating minimal signal degradation. Additionally, the device achieves broadband operation over a ~350 nm wavelength range, making it suitable for a wide array of photonic applications, including optical communication systems and on-chip signal processing. The comprehensive presentation of design parameters, supported by visual data, underscores the PRR’s practical viability and scalability in integrated photonics.
Keywords: Polarization Rotator, Birefringence, Photonic Crystals, Silicon Waveguide
