Blue band nonlinear optics and photodarkening in silica microdevices
Journal article, 2022
There are extensive studies to date on optical nonlinearities in microcavities at the near and mid-IR wavelengths. Pushing this research into the visible region is equally valuable. Here, we demonstrate a directly pumped, blue band Kerr frequency comb and stimulated Raman scattering (SRS) at 462 nm in a silica nanofiber-coupled whispering gallery microcavity system. Notably, due to the high optical intensities achieved, photodarkening is unavoidable and can quickly degrade the optical quality of both the coupling optical nanofiber and the microcavity, even at very low pump powers. Nonetheless, stable hyperparametric oscillation and SRS are demonstrated in the presence of photodarkening by taking advantage of in-situ thermal bleaching. This work highlights the challenges of silica-based, short wavelength nonlinear optics in high-quality, small mode volume devices and gives an effective method to overcome this apparent limitation, thus providing a baseline for optics research in the blue region for any optical devices fabricated from silica.
Author
Ke Tian
Okinawa Institute of Science and Technology Graduate University
Harbin Engineering University
Jibo Yu
Okinawa Institute of Science and Technology Graduate University
Harbin Engineering University
Fuchuan Lei
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Jonathan Ward
University College Cork
Angzhen Li
Okinawa Institute of Science and Technology Graduate University
Harbin Engineering University
Pengfei Wang
Shenzhen University
Harbin Engineering University
Síle Nic Chormaic
Okinawa Institute of Science and Technology Graduate University
Photonics Research
2327-9125 (ISSN)
Vol. 10 9 2073-2080Subject Categories
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1364/PRJ.459561