Room-temperature continuous-wave lasing at 318 nm on a relaxed AlGaN template grown on a sapphire substrate

Applied Physics Letters 2026

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Authors: Rintaro Miyake, Takumu Saito, Shogo Karino, Yusuke Sasaki, Shundai Maruyama, Shion Kamiya, Ryota Watanabe, Seiya Kato, Naoki Kitta, Y. Miyamoto, Rintaro Kobayashi, Kenta Kitagawa
+12 more Tomoya Tanikawa, Sho Iwayama, Hideto Miyake, Koichi Naniwae, Yoshito Jin, Masamitsu TORAMARU, Tatsuya Matsumoto, Yoshihiro Shimazaki, Hironori Torii, T. Takeuchi, Satoshi Kamiyama, M. Iwaya
DOI: 10.1063/5.0307059
Cited by: 4
References: 40

Abstract

Continuous-wave (CW) lasing at 318 nm is achieved at 20 °C from an ultraviolet B (UVB) laser diode grown on a relaxed AlGaN template atop a sapphire substrate. The device incorporates a refractive index-guided ridge-waveguide structure, high-reflectivity SiO2/Ta2O5 distributed Bragg reflector mirrors, and junction-down mounting on a polycrystalline AlN submount for enhanced optical confinement and heat dissipation. Under CW operation at 20 °C, the threshold current density and current are 4.3 kA cm−2 and 64 mA, respectively. These results demonstrate stable room-temperature CW lasing in an AlGaN UVB laser diode, likely advancing compact and manufacturable laser sources for medical and industrial applications.

Fields of Study & Subjects

GaN-based semiconductor devices and materials Photonic and Optical Devices Semiconductor Quantum Structures and Devices

Publication details

Journal / source
Applied Physics Letters
Publisher
AIP Publishing
Volume
128
Issue
2
Publication date
12 January 2026
Language
EN