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Overview

AWG with Flattened Spectral Response

Description

This application example illustrates a design of an Arrayed Waveguide Grating (AWG) simulated by employing star couplers and straight waveguides. In this example, the multigrating method [1] is used to achieve a flattened spectral response. Within this approach the grating between star couplers is separated into two sub-gratings. When these two peaks are slightly different, the final spectral response is flattened.

Typical Results

The setup for the design is composed of two star couplers (left and right) with a central array of waveguides in between (Figure 1). Random variations of the phase shift in the waveguides simulate phase errors which lead to crosstalk (Figure 2). The effect of non-optimized waveguide lengths can be analyzed. Results in Figure 3 are for constant length increments that make spectral responses for even and odd gratings shift to the lower and higher frequencies, respectively. Finally, Figure 4 and Figure 5 show the transfer functions of the AWG before and after optimization of the waveguide lengths for a flattened response.

Keywords

Arrayed Waveguide Grating, AWG, Multiplexer, Star Coupler, Optical planar waveguide components, Photonic Integrated Circuits, PICs