In this issue of ACS Nano, Nienhaus et al. report the optoelectronic properties of carbon nanotube chiral junctions with nanometer resolution in the presence of strong electric fields (μ1 V/nm). Here, we provide an overview of recent studies that combine scanning tunneling microscope (STM) and laser or microwave illumination. These techniques reveal nanoscale laser- or microwave-induced phenomena utilizing the intrinsic atomic resolution of the tunneling current, and do not require substantial modification of the STM itself. The merits of atomic-scale spatial resolution and chemical sensitivity of the laser or microwave spectroscopes make these techniques useful for nanoscale characterization.