Y. Hida

400-channel 25-GHz spacing arrayed-waveguide grating covering a full range of C- and L-bands

We realized a 400-channel 25-GHz spacing arrayed-waveguide (AWG) on a 6-inch Si wafer using 1.5%-/spl Delta/ silica-based waveguides. This AWG covers the full C- and L-bands and exhibits an on-chip loss of 3.8-6.4 dB.

Y-branch waveguides with stabilized splitting ratio designed by wavefront matching method

We designed optical Y-branch waveguides with a stabilized splitting ratio by using a new design approach based on the wavefront matching method. The designed Y-branches were fabricated using silica-based planar lightwave circuit technology. We suppressed any variation in the splitting ratio of the Y-branch experimentally and obtained excess losses of <0.35 dB over a wide wavelength range of 1.3-1.7 /spl mu/m.

12.5-GHz spacing compact and low-loss interleave filter using 1.5% /spl Delta/ silica-based waveguide

We describe the fabrication of a compact lattice-form waveguide interleave filter with a narrow channel spacing of 12.5 GHz. The circuit size was reduced to 1/4 the size of the original circuit by employing a novel folding layout and a waveguide with a high refractive index difference (/spl Delta/) of 1.5% that can reduce the minimum bending radius to 2 mm. The 12.5-GHz spacing interleave filter was fabricated on a single chip by using silica-based planar lightwave circuit technology. We achieved a low insertion loss of <2.3 dB, a wide 1-dB passband width of >8.1 GHz, a 20-dB stopband width of >7.3 GHz, a low crosstalk of <-25 dB, and a low chromatic dispersion of within /spl plusmn/300 ps/nm.

Arrayed-waveguide grating with built-in interferometer for measuring amplitude and phase distribution

We propose an arrayed-waveguide grating with a built-in interferometer that enables us to evaluate the amplitude and phase distribution in the arrayed waveguides easily and precisely. We fabricated the proposed optical circuit with silica waveguides, and successfully confirmed its operational principle in experiments.