J. Eur. Opt. Society-Rapid Publ. 22, 20( 2026) 189
Figure
2. The input and output values used for group velocity predictions, along with the resulting prediction – actual, residual – prediction, frequency – residual, and residual ratio comparison plots.
Figure 3. The input and output values used for bandwidth predictions, along with the resulting prediction – actual, residual – prediction, frequency – residual, and residual ratio comparison plots.
The geometry proposed by the model is tested using the MPB program, and the effective refractive index is calculated as ðn eff
¼�2:3). The minimum and maximum normalized frequency values are found to be 0.480 and 0.564, respectively. Based on these simulation results, the center frequency is defined as( f cen ¼ fmaxþ f min), and the corresponding bandwidth Df = 0.161 is then obtained. Herein, the
2
MEEP and MPB simulation frameworks employ dimensionless units, the target index-related parameters correspond to real-world wavelengths expressed in nanometers in the present study. If target wavelength is ½ k cen Š target
¼
1500 nm k minðmaxÞ ¼ k target minðmaxÞ simulation
½ k cen Š target: ð2Þ
½ Š simulation k cen
The wavelength range of 1388 – 1631 nm obtained using this relation covers the region encompassing the S, C, and L