Data-set supporting the paper “N-Rich Silicon Nitride Angled-MMI for coarse wavelength division (de)multiplexing in the O-band.” Optics Letters University of Southampton - ORC - Thalia Domínguez Bucio - tdb2g12@soton.ac.uk Date of data collection: September 2017 Date that the file was created: September 2017 Location of data collection: University of Southampton, U.K. License: Creative Commons Attributions Publications : The excel file contains experimental data for the paper: • Table 1 Optimised design parameters for the 3-channel AMMI • Fig. 2 Simulated spectral response for the 4-channel AMMI with optimised parameters Thetat = 0.3rad, Wa = 7.5mm and WMDW = 18mm. • Fig. 4 Spectral response of the demonstrated 4-channel AMMI on the N-rich SiN platform measured at 20°C. • Fig. 5 Sensitivity of the spectral shift as a function of the fabrication error in the width of the AMMI multimode waveguide observed in the O-band. • Fig. 6 Sensitivity of the spectral shift as a function of temperature variations exhibited by the AMMI in the O-band.