A monolithic microcavity laser with simultaneous upconversion and frequency-doubled lasing via crystal-in-glass engineering.

ABSTRACT: This work demonstrates a novel crystal-in-glass composite structure for multifunctional micro-nano light sources in integrated photonics. Based on a Er³⁺/Yb³⁺-codoped glass-ceramic (GC) whispering gallery mode (WGM) microcavity incorporating Ba₂TiGe₂O₈ (BTG) crystals, this microcavity enables dual-mode responses combining upconversion (UC) and frequency-doubled lasing. Made from a low-phonon-energy germanate glass matrix codoped with Er³⁺/Yb³⁺ for UC gain, the microcavity is crystallized to form BTG microcrystals for second harmonic generation (SHG). By leveraging the high-quality factor (Q ≈ 5.7 × 10⁴) and small mode volume, we achieve green (550 nm) and red (660 nm) UC lasing in a 30-μm-diameter micro

SUBMITTER: Ye S 

PROVIDER: S-EPMC12832608 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature