Low-loss channel waveguides with two-dimensional photonic crystal boundaries

We have used transmission measurements to estimate the propagation loss of submicron channels defined in two-dimensional photonic crystals patterned i nto a Ga(Al)As waveguide. The measured propagation loss of the fundamental mode is indistinguishable from the material absorption, setting an upper li mit of 50 cm(-1) (2 dB per 100 mum). We also find that, provided the etchin g is deep enough, propagation losses of these photonic crystal waveguides a re lower than those of ridge waveguides etched in the same run. (C) 2000 Am erican Institute of Physics. [S0003-6951(00)04144-9].