Feb 5 2013
In a parallel effort to its development of UV-C light emitting diodes (LEDs), HexaTech recently demonstrated optically pumped, AlGaN-based lasers grown on highest-quality, single crystalline AlN substrates.
Laser structures fabricated at HexaTech and tested in collaboration with North Carolina State University (NCSU) featured lasing thresholds as low as 85 kW/cm2 at wavelengths of 264 and 280 nm. This not only represents record-breaking laser performance, but also further validates the value proposition of HexaTech's AlN substrate platform for UV-C opto-electronic applications.
"Our recent results show convincing evidence of the feasibility of a solid-state UV-C laser," commented Dr. Andy Xie . "The tests not only demonstrate lasing at low pump intensities, but we also observed emission peak line widths as narrow as 0.02 nm, and further telltale signs of a properly operating laser, including spectrally resolved cavity modes, TE-mode polarization, and elliptically-shaped far-field patterns."
The observed lasing at low pump intensities is an important milestone toward the development of semiconductor lasers operating at short wavelengths in the UV-C range. Enabled by HexaTech's industry-leading, low dislocation density bulk aluminum nitride (AlN) substrates, these results add to the record-breaking UV-C LED and laser performance reported by other groups. The use of high-quality, native AlN substrates that are lattice-matched to the overgrown III-nitride device layers allow for fabrication of opto-electronic devices of superior structural quality, and, thus, previously unachievable performance.
There is a growing market opportunity for UV-C lasers used for chemical, biological, and explosive material detection. "HexaTech's core expertise in AlN crystal growth and wafer fabrication has already led to the development of world-class UV-C LEDs with previously unachievable device lifetimes," noted Joe Grzyb , HexaTech CEO. "Our AlN substrate platform, again, advances UV-C opto-electronics to new levels of performance."
Further technical details will be published in the scientific literature in the near future.