High-order dispersion in photonic crystal waveguides

High-order dispersion in the slow-light regime of photonic crystal (PhC) waveguides was measured by utilizing integrated Mach-Zehnder interferometer (MZI) structures, and compared with theoretical results obtained from 3D plane-wave calculations. Highly accurate measurements of group-velocity dispersion (GVD), third-order dispersion (TOD) and fourth-order dispersion (FOD) at high group-index (ng) values were enabled by minimizing external phase-distortions and increasing signal-to-noise ratio in the MZI. The experimental results for GVD, TOD, and FOD parameters at ng∼100 were ∼102ps2/mm, ∼104ps3/mm, and ∼105ps3/mm respectively. The results emphasize the importance of taking into consideration the effect of TOD and FOD on pulse broadening in the slow-light regime. © 2007 Optical Society of America.