InP-based planar photonic crystal waveguide in honeycomb lattice geometry for TM-polarized light.

We investigate manufacturable substrate-type photonic crystal waveguides relying on honeycomb lattice geometry, which shows large photonic bandgaps for TM-polarized light. To the best of our knowledge, air-hole-based photonic crystal slab waveguides with photonic bandgaps for TM-polarized light are experimentally demonstrated for the first time. The results are analyzed with numerical simulations based on the plane-wave expansion and the finite-difference time-domain method. The transmission spectra are measured, and a minimal propagation loss of 1600 dB/cm of TM modes at lambda=1520 nm for lattice constant a=590 nm is acquired with the cut-back method.