Compact arrayed-waveguide grating with multiple-arrowhead structures

A compact arrayed-waveguide grating (AWG) using multiple-arrowhead structures has been proposed. Arrowhead structures are useful for achieving low-cost and highly integrated waveguide devices because of their compactness. Therefore, the use of multiple-arrowhead structures enables us to achieve high-resolution AWGs with a channel spacing of less than IOGHz, and we have already fabricated an 8-channel, 25-GHz-spacing AWG using a single-arrowhead structure, a 16-channel, 100-GHz-spacing AWG using a double-arrowhead structure and an 8-channel, 6.25-GHz-spacing AWG using a triple-arrowhead structure. The dimension of the third type of AWG is much smaller than a conventional AWG, with a size ratio of 1 : 6.4. The levels of the losses and adjacent crosstalk are mainly determined by insertion losses in the v-bend waveguides and by phase shifts due to misalignment of the mirror position, respectively.