A team of researchers has developed the first chip-scale titanium-doped sapphire laser—a breakthrough with applications ranging from atomic clocks to quantum computing and spectroscopic sensors.

The work was led by Hong Tang, the Llewellyn West Jones, Jr. Professor of Electrical Engineering, Applied Physics & Physics. The results are published in Nature Photonics.

When the titanium-doped sapphire laser was introduced in the 1980s, it was a major advance in the field of lasers. Critical to its success was the material used as its gain medium—that is, the material that amplifies the laser’s energy. Sapphire doped with titanium ions proved to be particularly powerful, providing a much wider laser emission bandwidth than conventional semiconductor lasers. The innovation led to fundamental discoveries and countless applications in physics, biology, and chemistry.