We discuss the design and demonstration of 4-channel coarse wavelength-division (de-)multiplexers based on cascaded Mach-Zehnder interferometer (MZI) lattice filters and arrayed waveguide gratings (AWG) on a 150 nm silicon nitride (Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) platform. The 1 × 4 (de-)multiplexers are designed for a channel separation of 25 nm and operate within 990-1065 nm for bottom emitting vertical cavity surface emitting lasers (VCSEL)-based optical links. For Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> Gaussian AWGs, we demonstrate crosstalk <; -35 dB at the peak transmission band with insertion loss <; 0.5 dB. Measurements were performed over many dies, and pass-band standard deviations for channel 1-4 are 0.49, 0.66, 0.42, and 0.37 nm, respectively. Results for flat-top AWGs indicate crosstalk <; -20 dB, with insertion loss <; 3 dB for the best devices. Flat-top cascaded 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> order and 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> order MZI lattice filters show a minimum of crosstalk <; -15 dB and <; -20 dB, respectively. The pass-band temperature shift was determined to be 14.5 pm/°C, which is lower than reported values for silicon. The device footprint of the Gaussian and flat-top AWGs are both ~670 × 200 μm. The device footprint of the flat-top cascaded 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> order and 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> order lattice filters are 1160 × 470 μm and 1570 × 470 μm, respectively. We believe the Si3N4 platform has potential for its use in CWDM and possibly DWDM transceiver/optical-modules for data/computer communication in high temperature environments up to 80 °C.