"Synthetic Executable Companion: Transmission of Slow Light through Photonic Crystal Waveguide Bends"

"This simulator models the spectral dependence of optical transmission through 60-degree photonic crystal (PhC) waveguide bends fabricated in silicon-on-insulator. It captures three distinct spectral regimes: a slow-light regime near the waveguide cutoff, where bends become effectively opaque because of a mode-profile-induced blueshift of the cutoff wavelength; a linear low-dispersion regime with ultra-low bending loss of approximately 0.05 dB per bend; and a leaky regime below the light line. The simulator generates transmission spectra for straight waveguides and for structures containing 10 and 20 cascaded bends across two device families (hole radius r=0.23a and r=0.33a), including both simple and modified bend designs with four reduced-radius holes. The modified bends partially restore slow-light transparency by reducing the cutoff blueshift from about 15 nm to about 6 nm. This resource enables researchers to explore photonic crystal bend design tradeoffs, estimate transmission windows for slow-light circuits, and examine how hole radius, bend geometry, and the number of cascaded bends influence insertion loss across the photonic bandgap. It is presented as a synthetic executable companion for research exploration, reproducibility-oriented analysis, and education."