Image
The invisible beam from a high-power quantum cascade laser lights a match held by one of the authors (CG) in its path. The laser, which is 2.25 mm long and 17 µm wide, is housed in a cryostat at liquid-nitrogen temperature and emits an optical power in excess of 200 mW from each facet at a wavelength of 8.0 µm. In pulsed mode, similar devices emit up to 600 mW at room temperature.