Work

Deep-ultraviolet second-harmonic generation in a three-coherence-length SrB 4 O 7 microcavity

Year: 2026

Type: article

Abstract: We demonstrate deep-ultraviolet second-harmonic generation at 249.5 nm from a reflective vertical microcavity containing a SrB 4 O 7 layer three coherence lengths thick. With the fundamental beam blocked between settings, the second-harmonic signal showed near-quadratic power scaling. During uninterrupted upward power sweeps, the device exhibited a steeper, sweep-dependent response and reached a maximum observed average-power-normalized efficiency of 409% W −1 — approximately 157 times that of our previous 199 nm device using the same laser system [ Appl. Phys. Express 17 , 082004 ( 2024 ) 10.35848/1882-0786/ad69fe ]. Modeling based on atomic force microscopy measurements linked thickness variations to spectral broadening, while position-dependent measurements revealed larger-scale nonuniformity. Thermo-optic analysis indicated sensitivity to fundamental-wave resonance tuning. These results represent a milestone toward practical microcavity-based deep-ultraviolet and vacuum-ultraviolet sources.

Source: Optics Express

DOI: 10.1364/oe.615614

Authors: Tomoaki Nambu, Kazuki Matsumoto, Ryuma Matsuki, Keijiro Takashima, Masahiro Yoshiike, Kazuki Sato, Hiroyuki Togawa, Yusuke Mori, Masashi Yoshimura, Ryota Ishii, Masahiro Uemukai, Tomoyuki Tanikawa, Ryuji Katayama

Institutions: Institute of Laser Engineering, The University of Osaka, The University of Osaka, Stanley Electric (Japan), Kyoto University

Language: English

Topic: Photorefractive and Nonlinear Optics

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

OpenAlex ID: W7221135408

FWCI:

Cites: 36

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Related to: 10