Diode-pumped efficient high-power cascade Tm:GdVO₄ laser simultaneously operating at ∼2 μm and ∼2.3 μm

Abstract

The laser diode (LD)-pumped efficient high-power cascade Tm:GdVO4 laser simultaneously operating on the 3F4 → 3H6 (at ∼2 μm) and 3H4 → 3H5 (at ∼2.3 μm) Tm3+ transition was first reported in this paper. The cascade Tm:GdVO4 laser generated a maximum total continuous-wave (CW) laser output power of 8.42 W with a slope efficiency of 40%, out of which the maximum ∼2.3 μm CW laser output power was 2.88 W with a slope efficiency of 14%. To our knowledge, 2.88 W is the highest CW laser output power amongst the LD-CW-pumped ∼2.3 μm Tm3+-doped lasers reported so far.

Design and Integration of Vanadate Crystal-Based Tm and Ho Ion-Doped Gain Media for a Miniature Diode-Pumped 2.1 μm Laser

“…Compared with the intracavity-pumped Ho laser using the same crystals (Figure ), the endurable pump power is enhanced by 33% and the maximum Ho laser power is increased by more than 8 times. The obtained Ho laser power is the maximum power of the diode-pumped vanadate gain media with a wavelength of above 2 μm at room temperature. − We attribute this to the superiority of the composite gain structure, where an additional bonded Ho:YVO 4 section with a low quantum deficit can significantly relieve the thermal stress by the bonding interface, increase the acceptable LD pump power, and decrease the thermal lensing with improved beam quality. At the maximum Ho laser power, beam quality factors are measured to be with M x 2 =1.33 and M y 2 = 1.52 along the horizontal and vertical directions, respectively (Figure b).…”

“…This is useful to deal with the thermal effects by sacrificing the lasing efficiency and the slope efficiency was 13.5% . Moreover, the gain length should be increased for sufficient pump absorption, − which challenges the design and miniaturization of these lasers.…”