Near-Field Microscope Probe for Far Infrared Time Domain Measurements
24 July 2000
A near-field probe fabrication technique for far infrared frequencies based on photoconducting antennas is developed. Subwavelength- size field source is accomplished by means of an aperture and protruding high refractive index tip. The near-field probe is tested using free space traveling electrmagnetic pulses with a broadband spectrum in the range of 0.3-1.5 THz. A spatial resolution of 60microns was achieved for a 50microns-aperture. The described probe may be used for near-field transmission microscopy in illumination and collection modes. Resolution may be further improved by means of a smaller aperture.