Design and experimental demonstration of photonic-crystal lasers with multijunction active layers

TL;DR

This paper presents a novel multijunction active layer design for photonic-crystal surface-emitting lasers, achieving significantly higher efficiency and output power through innovative design and fabrication.

Contribution

It introduces a multijunction active layer structure for PCSELs that enhances efficiency and power, demonstrating a record-high output power and improved slope efficiency.

Findings

Achieved a slope efficiency of 1.58 W/A, over twice that of single-junction PCSELs.

Demonstrated a record-high peak output power of 1.8 kW for PCSELs.

Designed a multijunction PCSEL that avoids optical absorption in tunnel junctions.

Abstract

We introduce multijunction active layers, featuring a stack of alternating active layers and tunnel junctions, to PCSELs to increase their slope efficiency, which is vital for various applications including laser processing and LiDAR. First, we design a multijunction PCSEL that avoids optical absorption in the heavily-doped tunnel junctions while allowing sufficient optical gain and resonance effects in the active and photonic crystal layers. Next, we fabricate a 3-mm-diameter two-junction PCSEL, achieving a slope efficiency of 1.58 W/A, which is over twice as high as that of conventional single-junction PCSELs, and a record-high peak output power of 1.8 kW for PCSELs.