A simple scanning head for scanning near-field optical microscope

A novel scanning head for a scanning near-field optical microscope (SNOM) is developed. The sample is mounted at the top of a piezo scanning tube, and the sample can be translated manually in its plane at 3 mm range. The principle of the translation mechanics is based on the scanning tube tilting around its 'root point', so that the head contains no sliding parts. This approach allows to overcome jamming problems caused by lubricant or water vapor freezing between the parts at low temperatures. The feedback is based in shear-force laser sensor. Two different modifications, one for the room temperature and the other for the temperature range 4.2-300 K are developed. High stability and good mechanical precision of the room-and low-temperature device versions is demonstrated in the SNOM mode. The problems of thermal stability are discussed in terms of very high-quality factor of the fiber tip at low temperatures. (C) 1998 Published by Elsevier Science B.V. All rights reserved.