Sasha’s early work included the development of a frequency-stabilized diode lasers for laser spectroscopy. Developed as a part of his thesis work in late 70s and 80s, such a laser is by now an indispensable tool in our field of research. Sasha also carried out pioneering spectroscopy experiments using the diode lasers, including demonstrations of frequency locking of such lasers to each other and to the absorption lines of atomic systems.

Sasha’s work in 90’s as a visiting scientist at National Institute of Standards and Technology, and, later as a Research Professor at Texas A&M University involved the realization of lasers without inversion, the realization of resonantly enhanced index of refraction without absorption, as well as developments of novel methods for laser spectroscopy based on electromagnetically induced transparency. Sasha also played an important role in the Texas A&M experiments on ultra-slow light that eventually resulted in a new research direction involving stopped light and quantum information storage in atomic ensembles.

As a Research Associate at Harvard, his work includes experiments on generation and storage of quantum states of light in atomic ensembles, resulting in a new research direction on realization of quantum repeaters and quantum information processing in atomic ensembles; experiments on quantum manipulation of individual spin impurities in diamond, their coherent coupling to optical photons and applications to nanoscale sensing.