Illinois researchers demonstrate new quasi-periodic semiconductor lasers

Researchers in Illinois have successfully demonstrated a quasi-periodic photonic-crystal surface-emitting laser (QPCSEL), offering a more versatile method for creating advanced semiconductor lasers. The findings, published in Applied Physics Letters, address a long-standing challenge in the field: the reliance on geometry-dependent device fabrication.

Traditionally, photonic-crystal surface-emitting lasers (PCSELs) utilize repeating patterns that limit the ability to fabricate devices with diverse shapes and sizes. To overcome this, graduate student Erin Raftery, working in professor Kent Choquette’s lab, developed a method to create a non-periodic structure. By etching a silicon dioxide layer and covering it with epitaxial semiconductor using a buried dielectric platform, the team created a partially periodic structure that lased successfully at room temperature.

This new approach provides a practical route for developing high-performance, fully integrated QPCSELs that are more tunable, reliable, and independent of specific geometries. Such advancements are particularly relevant for defense and aerospace applications.