Laser characteristics at 1535 nm and thermal effects of an Er:Yb phosphate glass microchip pumped by Ti:sapphire laser

A Taper-Fused Microspherical Laser Source

“…We study the maximum pump power that can be launched into an IOG2 sphere before the onset of thermal stress. A similar effect, leading to thermal damage, was reported for a microchip laser [7], but with higher pump powers. We show that this thermal effect can be used to fuse the cavity to a tapered fiber, thereby realizing an integrated coupler plus lasing source for L-band emissions.…”

Two-photon luminescence thermometry: towards 3D high-resolution thermal imaging of waveguides

“…This fact suggests that pump-induced thermal effects in Er:Yb glass waveguides cannot be neglected at all and should be seriously considered during design and operation of such devices. These pump-induced thermal loadings have been, indeed, found to be comparable [14] in a Er:Yb phosphate glass microchip laser, and much larger than lasers in Yb doped crystals [15,16] and Er:Yb codoped fibers [17][18][19][20].This large pump induced thermal loading could be due to the large pump laser densities achieved in our waveguides in which 980 nm pump radiation is confined between damage tracks separated only 17 µm. iii)…”

“…It has been proposed and experimentally demonstrated in previous works that time modulation of pump radiation could be used for efficient reduction of thermal loading. When the time distance between consecutive pump pulses (i.e., pulse separation) is larger than the characteristic thermal relaxation time (τthermal), thermal accumulation between consecutive laser pulses is minimized resulting on a reduced average heating [14,19]. This possibility has been demonstrated to be especially suitable for the optimization of the laser performance of microchip lasers that are also characterized by large pumpinduced thermal loadings of the active volume [xx].…”

Thermo-optical tuning of whispering gallery modes in Er:Yb co-doped phosphate glass microspheres

“…The main transition processes for Er:Yb phosphate glass pumped around 978 nm have been extensively described elsewhere [10,15,16]. Boltzmann statistics can be used to describe the strong thermal coupling and the population redistribution between the 2 H 11/2 and 4 S 3/2 erbium energy levels that lead to green emissions at 530 nm and 554 nm respectively on decay to the **** The largest measured 530:554 nm intensity ratio for IOG-2 is 3.5, equivalent to a temperature over 800 K [18].…”