We show, for the first time, dense WDM (8×20 Gbit/s) transmission at 2 μm enabled by advanced modulation formats (4-ASK Fast-OFDM) and the development of key components, including a new arrayed waveguide grating (AWGr) at 2 μm. The AWGr shows -12.8±1.78 dB of excess loss with an 18-dB extinction ratio and a thermal tunability of 0.108 nm/°C.