We recently demonstrated a molecular gas laser that emits at frequencies between 250 GHz up to almost 1 THz using nitrous oxide (commonly known as laughing gas) as the gain medium. This laser relies on the optical pumping of the gas by a quantum cascade laser and can be generalized to a large number of gas molecules for additional tunability and a broader frequency range. This new laser will potentially be useful for various applications in imaging, security or astronomy. This work was done in collaboration with MIT and the US Army with experimental work done here in the Capasso Group. This work was published in Science and can be found here. See a press release from Harvard SEAS here.