Narrow-Linewidth 1550 nm Semiconductor Lasers with a Broad Operating Current Range

Narrow-linewidth 1550 nm semiconductor lasers with a broad operating current range are essential light sources for coherent photonic systems, offering low phase noise, high spectral purity, and robust operation.This invited talk presents recent advances from the University of Glasgow's Photonic Integrated Circuit (PIC) research group in laser cavity engineering and topological photonics, enabling substantial linewidth reduction while maintaining stable single-mode operation over an extended operating current range.