 During his time as a fellow, he served as a visiting scientist at Massachusetts Institute of Technology's George Harrison Spectroscopy Laboratory.There he developed with Stephen Coy the technique of microwave-detected, microwave-optical double resonance, which permits the automatic assignment of complex spectra.Appointed to the chemistry faculty of Princeton University in 1985, Lehmann received both the Henry and Camille Dreyfus Award for new faculty and the Presidential Young Investigator Award from the National Science Foundation in his first year with the university.