AlGaN-based deep ultraviolet vertical-cavity surface-emitting lasers on a flexible substrate

Area of Science:

• Optoelectronics
• Materials Science
• Semiconductor Physics

Background:

• Flexible electronics are crucial for next-generation devices.
• Vertical-cavity surface-emitting lasers (VCSELs) offer unique advantages for light source applications.
• Deep ultraviolet (DUV) light sources are essential for various scientific and industrial applications.

Purpose of the Study:

• To demonstrate AlGaN-based deep ultraviolet (DUV) VCSELs on a flexible substrate.
• To explore the fabrication of flexible DUV photonic devices.
• To investigate the lasing characteristics of DUV VCSELs on flexible platforms.

Main Methods:

• Fabrication of AlGaN quantum well heterojunctions.
• Selective removal of a GaN sacrificial layer via electrochemical etching.
• Transfer of the heterojunction onto a flexible substrate.
• Deposition of dielectric distributed Bragg reflectors (DBRs) to form the resonant cavity.

Main Results:

• Successful demonstration of AlGaN-based DUV VCSELs on a flexible substrate.
• Achieved single-mode lasing at 294.2 nm with a threshold power density of 7.4 MW/cm².
• Observed multimode lasing attributed to DBR non-uniformities.
• Lasing performance was confirmed at room temperature with a linewidth of 0.39 nm.

Conclusions:

• This work presents a viable method for creating flexible DUV VCSELs.
• The developed technology paves the way for flexible photonic integration in the DUV spectrum.
• Enables new possibilities for smart light sources and multifunctional flexible photonic platforms.