Elmer Samuel Imes (October 12, 1883 – September 11, 1941) was an internationally renowned American physicist who made important contributions in quantum, demonstrating for the first time that Quantum Theory could be applied to the rotational energy states of molecules, as well as the vibration and electronic levels. Imes's work provided an early verification of Quantum Theory, and his spectroscopy instrumentation inventions, which include one of the earliest applications of high resolution infrared spectroscopy, led to development of the field of study of molecular structure through infrared spectroscopy.