title: Modeling and design of irregularly arrayed waveguide gratings.
abstract: In this paper we propose a concept of irregularly arrayed waveguide gratings (IAWGs). By replacing regularly arrayed waveguides of conventional AWGs with irregularly arrayed ones, we found theoretically that the IAWGs have arbitrary free spectral ranges and are suitable to provide a large number of channels with relatively smaller circuit regions. A Fourier optics model is presented, which is able to calculate the transmission characteristics between any arbitrary pair of input/output ports in either conventional AWGs or IAWGs. As an example, a 1080-channel IAWG with 0.199 nm spacing is designed and simulated. Results show this device can be contained in a 6-inch wafer and provide two work patterns: all 1080 channels with a relatively high crosstalk of about -20 dB, and 128 successive channels which can be arbitrarily moveable over the range of the 1080 channels with a crosstalk of about -32 dB.
authors.forename: Feng
authors.initials: F
authors.lastname: Xiao
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Li
authors.forename: Anshi
authors.initials: A
authors.lastname: Xu