Silicon　nitride　(SiN)　is　an　ideal　material　which　is　compatible　with　complementary　metal-oxide-semiconductor　(CMOS)　technology.　Its　advantages　include　suitability　for　a　large　spectral　range,　low　propagation　loss　and　low　thermo-optic　coefficient,　etc.　Wavelength　division　(de)multiplexing　(WDM)　device　is　a　crucial　component　for　optical　transmission　networks.　In　this　paper,　we　demonstrate　a　six-channel　WDM　device　built　with　angled　multimode　interferometer　(AMMI)　structure　in　SiN　material.　Using　the　first-　and　second-order　self-imaging　effects　in　the　multimode　waveguides,　the　number　of　the　multiplexed　channels　is　increased　from　3　to　6,　without　increasing　the　overall　length　of　the　device.　The　device　is　designed　to　operate　in　the　C+L　band,　and　the　central　wavelength　spacing　between　the　neighboring　channels　is　20nm.　The　simulation　results　show　that　the　insertion　loss　of　the　device　in　each　channel　is　less　than　0.81dB　and　the　averaged　crosstalk　of　the　channels　is　∼14.9dB.　Meanwhile,　the　device　also　exhibits　low　temperature　sensitivity　and　large　fabrication　tolerance,　which　is　suitable　for　mass　production　in　commercial　foundries.　©　COPYRIGHT　SPIE.　Downloading　of　the　abstract　is　permitted　for　personal　use　only.