Using a data set of 1041 boreal lakes along a 13° latitudinal gradient, sampled in 1995, 2000, and 2005, and an additional data set of 90 lakes along a 1000-m altitudinal gradient at 68°N, we show ...
This study reveals advancements in THz nonlinear optics with graphene, achieving substantial gains in harmonic generation for future communication systems.