A terahertz scanning near-field optical microscope with an attenuated total internal reflection module

Abstract

The first terahertz scanning near field optical microscope with an attenuated total internal reflec tion module and a free electron laser (FEL) as the radiation source was developed. A scanning system with positioning using a confocal sensor with chromatic coding and a surface-subwavelength probe touch sensor were developed and tested. A new technique for sensing the distance between the probe and a conducting sur face via corona discharge current measurement was developed. A specific lock in system for detection of probe scattered pulse-periodic radiation, which includes a hot electron superconducting bolometer and an electronic signal storage circuit, was developed to operate with the Novosibirsk terahertz FEL. All elements of the microscope were tested, and their working capacity was demonstrated. Experiments on the detection of microscope probe scattered terahertz radiation have been initiated.