Laser Terahertz Emission Nanoscopy with Blue Pump Pulses

We describe the first demonstration of s-SNOM using blue light. Using femtosecond pulses at 410 nm, we generate THz emission from bulk InAs and show that these near-field signals provide spectroscopic information that cannot be obtained using near-infrared pulses. Next, we generate near-field THz emission images directly from bulk silicon and develop a novel theoretical framework to correlate them directly to the silicon's local carrier concentration.