 A few years later, in 1980, the first high-resolution (with a frequency up to 500 MHz) through-transmission SAM was built by R.Gr.Maev and his students at his Laboratory of Biophysical Introscopy of the Russian Academy of Sciences.First commercial SAM ELSAM, with a broad frequency range from 100 MHz up to 1.8 GHz, was built at the Ernst Leitz GmbH by the group led by Martin Hoppe and his consultants Abdullah Atalar (Stanford University), Roman Maev (Russian Academy of Sciences) and Andrew Briggs (Oxford University.)