University of Illinois researchers develop tunable QPCSEL semiconductor lasers

Researchers at the University of Illinois Urbana-Champaign have developed a new type of photonic-crystal surface-emitting laser (PCSEL) that utilizes a quasi-periodic structure. This new approach, referred to as a QPCSEL, aims to overcome the limitations of traditional PCSELs, which rely on repeating geometric patterns that can be difficult to fabricate with diverse properties.

Led by professor Kent Choquette, the team, including graduate student Erin Raftery, utilized a buried dielectric platform to create a more flexible and tunable device. Instead of etching holes vertically through semiconductor layers, the researchers patterned a silicon dioxide layer and covered it with epitaxial semiconductor material. This method allows for non-periodic patterning, providing greater control over the refractive index variation. The resulting device successfully produced laser light at room temperature, offering potential advancements for applications in aerospace and defense.