Properties of Cat-Whisker Antennae for a 3.39 μm He-Ne Laser

Radiation patterns of the cat-whisker antenna for a 3.39 μm He-Ne laser have been observed and interpreted by means of the long-wire antenna theory. It is found that some of the patterns are obtained by a single long wire antenna, which is given by the etched-away section, and the others are obtained by two long wire antennae, which are given by the etched-away section and the etched-away plus a 10-μm-diam rod section. The observed pattern depends on the condition of the edge between the etched-away and the 10-μm-diam rod sections.