Cooperative luminescence in an ytterbium-doped silica fibre

Ultralow-threshold laser and blue shift cooperative luminescence in a Yb3+ doped silica microsphere

“…This is due to the huge power density over long interaction time. 12 The high Q value microsphere resonator with high density energy near surface of the orbit makes it possible to achieve huge circulating optical pump power in microscale mode volumes(∼1GW/cm 2 ), 20 this result in ultra-low laser oscillation. In addition, long confinement time makes it possible to wrap a large interaction distance into a tiny volume, 18 hence the high density energy and the limited Yb 3+ ions in small volumes result in the saturation effect.…”

“…The specific CL is located in the blue region, which has potential application in three-dimensional display. 7 Although CL has been investigated in a variety of nanophosphors, glasses, and wave-guiding systems, [8][9][10][11][12][13][14][15][16][17] some of their features remain unclear. Silica microsphere resonators with whispering gallery modes (WGMs) posse the characteristics of ultrahigh quality factor (Q) and small modal volumes, which can drastically reduce the pump power required to generate laser emission and nonlinear effects.…”

Multi-wavelength visible up-converted luminescence in novel heavily doped Ytterbium–Holmium silica fiber under low-power IR diode pumping

“…We show that the conventional mechanisms of energy migration from Yb 3+ to Ho 3+ and stepwise up-conversion within the Yb 3+ -Ho 3+ mixed system that is a consequence of a series of excited-state absorption (ESA) transitions are the processes highly effective in the Yb-Ho fiber as those in crystals [11][12][13][14][15][16][17][18][19]. We also discuss an avalanche-like character of the up-conversion process in the fiber and an additional channel of excitation of the Ho 3+ sub-system via an energy transfer from the Yb 3+ ion pairs [20][21][22][23].…”

Near-IR-to-visible emission in ytterbium-doped silica fiber at in-core 488-nm pumping

“…1, where no tracks of these dopants are seen. Therefore, the green emission (near 0.5 μm) can be solely attributed to the cooperative emission, which stems from the presence in the YF of Yb 3+ -Yb 3+ pairs [21][22][23][24]. Also, the presence of absorption near 0.5 μm may be explained by the cooperative absorption effect, which has been recently observed in heavily doped ytterbium and ytterbium-holmium silica fibers [24][25][26].…”