Demonstration of Compact and Low-Loss Athermal Arrayed-Waveguide Grating Module Based on 2.5%-Δ Silica-Based Waveguides

We demonstrated a compact and low-loss athermal arrayed-waveguide grating (AWG) module utilizing silica-based planar lightwave circuit (PLC) technology. Spot-size converters based on a vertical ridge-waveguide taper were integrated with a 2.5%-Delta athermal AWG to reduce the loss at chip-to-fiber interface. Spot-size converters based on a segmented core were formed around resin-filled trenches for athermalization formed in the slab to reduce the diffraction loss at the trenches. A 16-channel athermal AWG module with 100-GHz channel spacing was fabricated. The use of a 2.5%-Delta athermal chip with a single-side fiber array enabled a compact package of the size of 41.6 x 16.6 x 4.5 mm(3). Athermal characteristics and a small insertion loss of 3.5-3.8 dB were obtained by virtue of low fiber-to-chip coupling loss and athermalization with low excess loss. [DOI: 10.1143/JJAP.47.7903]