For very high intensity beams of light, two photons, each with half that minimum energy, can be absorbed simultaneously.

He also published highly cited foundation papers on the electronic, optical, and vibrational properties of III-V semiconductors, silicon, and germanium.

[9] In 1964 Braunstein became a professor of physics at University of California, Los Angeles (UCLA), where he remained for the rest of his career.

[10] Some of Braunstein's work was theoretical, including the proposal that neutral atoms could be scattered by a sufficiently intense standing wave of light.

The effect with neutral atoms is much weaker, but was finally observed nearly 20 years after the proposal of Braunstein and his co-authors.