Polarization insensitive waveguide grating routers in InP

We demonstrate a 16-channel waveguide grating router (WGR) in the InP-based material system. The channel spacing of the WGRs is 100 GHz and the maximum interchannel crosstalk is -28 dB. The polarization related (TE-TM modal) wavelength shift is approximately 0.08 nm and the polarization dependent variation in peak signal is less than 0.2 dB. 2.60-μm-wide ×1.90-μm-thick raised-stripe InGaAsP Quaternary (/spl lambda//sub g/=1.17 μm) waveguides on an n-type InP substrate make up the basis paths of the WGR. We describe the design, fabrication and the results of measurement of the 16-channel polarization-insensitive WGR.