Duncan G. Steel (born 1951) is an American experimental physicist, researcher and professor in quantum optics in condensed matter physics.

[1] Prior to joining the faculty at Michigan, he was a Member of the Technical Staff and Senior Staff Physicist for the Hughes Aircraft Company at the Hughes Research Labs (HRL) in Malibu.

Working with Richard Lind, they demonstrated the first laser with a phase conjugate mirror using degenerate four-wave mixing.

[3] Steel works on nonlinear optical spectroscopy and coherent control of semiconductor heterostructures, for which he received 2010 Frank Isakson Prize for Optical Effects in Solids from the American Physical Society.

In addition to semiconductor physics, he is also involved in the development and application of advanced laser spectroscopy methodology and other biophysical techniques for the study of protein folding and dynamics.