An improved far-infrared microscope with quantum Hall detectors

A highly-sensitive scanning far-infrared (FIR) microscope is developed. The microscope consists of a silicon solid immersion lens that probes FIR and a condenser lens that focuses the FIR onto a small and highly-sensitive quantum Hall detector. The solid immersion lens is in contact with a sample, which is moved with a mechanical stage. The microscope is successfully applied to image extremely weak cyclotron emission from quantum Hall devices with a spatial resolution about View the MathML source and a signal-to-noise ratio improved by a factor 18 compared to a previous system.