Hybrid booster at 1940  nm based on Tm:Lu_2O_3 ceramics implementing fiber combined signal and pump sources

Abstract

A novel concept of a booster amplifier for a pulsed Tm fiber laser at 1940 nm based on Tm:Lu2O3 ceramics and implementing fiber-combined signal and pump was examined. The pumping emission of the ceramics at 1678 nm was obtained from Raman-shifted Er fiber laser radiation. The hybrid fiber-ceramics amplifier with a gain factor of up to 6 dB and a pulse energy of more than 650 μJ with single-mode output was demonstrated.

Enhanced ∼2 μm Emission of Tm3+ in Lu2O3 by Addition of a Trace Amount of Er3+

“…The absorption of the Tm 3+ ion in Lu 2 O 3 is around 796 nm and matches well with commercially available GaAlAs laser diodes . In the past decades, Lu 2 O 3 :Tm 3+ realized 2.03–2.10 μm lasers in forms such as CW lasers, Q-switched lasers, mode-locked lasers, and thin-disk lasers. − The laser with Lu 2 O 3 :Tm 3+ has been applied as a hybrid booster, in optical parametric oscillation (OPO), as a pump source, etc. , …”

“…10−14 The laser with Lu 2 O 3 :Tm 3+ has been applied as a hybrid booster, in optical parametric oscillation (OPO), as a pump source, etc. 15,16 When the 3 H 4 level of Tm 3+ is excited, the 3 F 4 level (∼2 μm) of Tm 3+ is populated by a cross-relaxation (CR) process. 17,18 This process occurs between two nearby Tm 3+ ions and is essentially a quantum cutting phenomenon.…”

High efficiency in-band pumped Tm- and Ho-doped 2-μm solid-state lasers

“…A double-wavelength operation at 2066 nm and 1967 nm of the linear-cavity Tm 3+ :Lu2O3 ceramics lasers in-band pumped at 1670 nm was demonstrated in [18]. An efficient booster amplifier for a pulsed fiber laser at 1940 nm based on Tm 3+ :Lu2O3 ceramics with fiber-laser pumping at 1670 nm was also reported in [25].…”

“…The in-band pumping of the 3 H6-3 F4 Tm 3+ -ion transition enables the high-efficiency and high-power operation of Tm 3+ -doped lasers at 1900-2100 nm with a low quantum defect [12][13][14][15][22][23][24][25][26][27]. Direct excitation of Tm 3+ ions into the upper laser level 3 F4 results in the reduced thermal load and high laser efficiency compared to the diode pumping into 3 H4 level with the cross relaxation ( 3 H4, 3 H6) → ( 3 F4, 3 F4).…”

“…Direct excitation of Tm 3+ ions into the upper laser level 3 F4 results in the reduced thermal load and high laser efficiency compared to the diode pumping into 3 H4 level with the cross relaxation ( 3 H4, 3 H6) → ( 3 F4, 3 F4). The high-efficiency lasers and amplifiers based on Tm 3+ :YLF or Tm 3+ :CaGdAlO4 crystals, and Tm 3+ :YAG, Tm 3+ :Lu2O3 or Tm 3+ :Y2O3 ceramic with the in-band pumping at 1615 nm and 1670-1678 nm were recently reported in a number of papers [23][24][25][26][27]. The 2-µm lasers based on the highly-Tm 3+doped YAG, YAP and YLF crystals with 1695 nm diode pumping were also presented [28].…”