Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Upconverted emission spectra under low and high excitation density. For the low excitation power, the green state was not yet saturated. The intensities may be compared. New peaks (italic) are assigned: 2H9/2 → 4I15/2 transition at 410 nm, 4I9/2 → 4I15/2 transition at 815 nm, and the intermediate transition 2H9/2 → 4I13/2 at 560 nm.
