Suppression of polarization dependence in the design of an arrayed-waveguide grating with photodefinable polyimide

We report on an effective means of suppressing polarization dependence in the design of an arrayed waveguide grating (AWG) made of photodefinable polyimide. The polarization dependence of the arrayed-waveguide grating device is excellently suppressed by controlling the grating order (m) for a given refractive index difference between TEand TM-modes within polyimide. The transmission characteristics of two AWGs for two grating orders, m ¼ 70 and 90, show wavelength shift of 5.04 nm and nearly zero, respectively, strongly supporting and confirming the method that we have identified for the birefringence suppression. 2002 Elsevier Science B.V. All rights reserved.