Passively Q-Switched Integrated Tm: YAG/Ho:YAP Laser

Cr3+↔Fe3+ Energy Transfer Offset Enabling Anti‐Thermal Quenching Near‐Infrared Emission for Coded Wireless‐Communication Applications

“…Transition-metal Cr 3+ (3d 3 )-doped phosphors are considered an ideal candidate for NIR phosphor-converted lighting emitting diodes (NIR pc-LEDs) applications, owing to their tunable broadband emission ( 4 T 2 → 4 A 2 ) peaking at ≈720-1200 nm, and their absorption matches well with that of the commercial blue InGaN chip. Therefore, numerous Cr 3+ -doped NIR phosphors have been developed [13] ; however, it is a fundamental challenge to achieve anti-TQ broadband emission. Actually, the previous investigations showed that, if the emitting state of the activators could be populated by some heat-based route (such as energy transfer from defect levels to the related emitting state), the TQ issue could be resolved, in theory.…”