Laser induced thermochromism and reversible upconversion emission modulation of a novel WO3:Yb3+,Er3+ ceramic: dual-modal fingerprint acquisition application

The quick and accurate identity recognition can be obtained by the acquisition of fingerprints in the financial, telecommunication, transportation, education and medical fields. However, conventional fingerprint acquisition technologies have many problems such as the high background interference, low detection sensitivity and complicated operation. In this work, the reversible modulation of laser induced thermochromism and upconversion luminescence of a novel WO3:Yb3+,Er3+ ceramic was achieved even after several cycles, exhibiting excellent repeatability. For the first time, we realized the dual-modal fingerprint acquisition by means of the laser induced thermochromism and upconversion luminescence of WO3:Yb3+,Er3+ ceramic. Particularly, this method shows ultrahigh stability, preserving the fingerprint patterns as long as one year. The results demonstrated that our technology is nondestructive, repeatable, highly effective and stable, paving the way for the development of the acquisition and storage of fingerprints.