Optical performances analysis and structure parameters optimization design of dense arrayed waveguide grating

Abstract The core device of dense wavelength division multiplexing (DWDM) system is a wavelength division multiplexer/demultiplexer, among which the arrayed waveguide grating (AWG) device has the most superior optical performances. The optical performances of AWG are mainly affected by the structure parameters such as the waveguide spacing, the width and length of the tapered waveguide and the number of arrayed waveguides. Taking the 40-channel AWG as the research object, by combining theory with simulation, this paper analyzed the influence mechanisms and laws of AWG structure parameters on its optical performances including insertion loss, loss non-uniformity, adjacent crosstalk, and 3 dB bandwidth. Then, the sensitivities analysis of AWG optical performance was carried out by using the direct derivation method and the finite difference method in the sensitivities analysis method, so as to obtain the influence degree of each structure parameter on the optical performances. Finally, based on the influence rules and sensitivities of structure parameters on optical performances, this paper adopted some methods to optimize the structure parameters of AWG, and optimized the insertion loss, loss non-uniformity, adjacent crosstalk, and 3 dB bandwidth to about 1 dB, 0.35 dB, −30 dB, and 0.42 nm, respectively. The research methods and conclusions of this paper can provide references for the optimization of optical performances and layout design of other types of AWG.