Inorganic Compound Could Replace Laser Dyes

An inorganic compound may serve as a longer-lasting replacement for laser dyes in a variety of applications.

A team from the Spanish National Research Council (CSIC) and the Academy of Sciences of the Czech Republic, developed a laser whose medium is borane, a substance “based on boron hydrides, inorganic cluster compounds with a rich and diverse chemistry,” according to the study published in Nature Communications (doi: 10.1038/ncomms6958).

A laser solution. Images courtesy of Spanish National Research Council/Academy of Sciences of the Czech Republic.

Borane presents efficient and degradation-resistant laser emission in the blue spectral region, making it suitable for applications such as spectroscopy and materials processing. The researchers demonstrated that the borane solution anti-B₁₈H₂₂, under pulsed excitation, can emit at 406 nm. The solution has an efficiency of 9.5 percent and “a photostability superior to many of the commercially available state-of-the-art blue laser dyes,” the study notes.

“We have concentrated our work on solutions of anti-B₁₈H₂₂, a cluster-like molecule with architecture resembling that of a split soccer ball,” said Dr. Michael Londesborough, borane specialist at the Institute of Inorganic Chemistry at the Academy of Sciences.

Borane is similar to organic dyes in structure and properties, the researchers said, which allows it to emit the laser light in an efficient and tunable way. And its resistance to degradation could reduce the number of times a laser’s liquid medium has to be replaced. This helps boost cost efficiency and eliminates occupational hazards and environmental impact due to the handling of toxic, flammable solvents.

“We are highly excited by this discovery,” Londesborough said. “The boranes, with their unique molecular structures and high photostabilities, present a new and previously untapped resource for laser technology.”

A model of a borane molecule.

The researchers plan to synthesize new boranes emitting at other wavelengths, which they said could benefit applications such as dermatology, and potentially treatment of vascular and other diseases.

“There is still plenty of work to be carried out before these compounds can reach the commercial shelves, but the scientific relevance of this discovery represents a milestone in the history of lasers, since there are not many occasions in which a new family of laser materials is unveiled,” said postdoctoral fellow Luis Cerdán, a CSIC researcher at the Institute of Physical Chemistry Rocasolano.

For more information, visit www.csic.es.