Abstract: Recently,research on negative-index material has become a hot frontier topic in physics,which not only attracted extensive public attention with lots of related pictures appearing online,but also have been selected by some university teachers in related course teaching. Here,we systematically study the imaging problems for a chopstick or a sphere put into a cup filled with negative-index＂water＂. Our results not only clarify some misunderstandings existing in current public medium related to such problems,but also enrich our knowledge of negative-refraction imaging. We hope this work can provide valuable assistance to teaching relevant knowledge in related courses.

Key words: negative-index materials, imaging