A storage Dewar near-field scanning optical microscope

A near-field scanning optical microscope for operation within a storage Dew ar is described. It was designed for studies of opaque samples and operates in the collection mode. Illumination can be either through the tip or from the side via a separate fiber. Scans can be begun within 2 h after start o f cooldown. Its rigid design allows high resolution and long scans with no additional vibration isolation. To illustrate its performance, measurements of photoluminescence in GaAs/AlGaAs heterostructures are presented. The si gnal and noise levels for the two illumination modes are examined. (C) 2000 Elsevier Science B.V. All rights reserved.