Applied Sciences (Dec 2023)

Continuous-Wave and Mode-Locked Operation of an In-Band Pumped Tm,Ho,Lu:CaGdAlO<sub>4</sub> Laser

  • Huangjun Zeng,
  • Wenze Xue,
  • Robert T. Murray,
  • Weidong Chen,
  • Zhongben Pan,
  • Li Wang,
  • Chen Cui,
  • Pavel Loiko,
  • Xavier Mateos,
  • Uwe Griebner,
  • Valentin Petrov

DOI
https://doi.org/10.3390/app132312927
Journal volume & issue
Vol. 13, no. 23
p. 12927

Abstract

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We investigate in-band pumping of a Tm,Ho,Lu:CaGdAlO4 laser using a Raman-shifted Er-fiber laser (1678 nm), in the continuous-wave (CW) and mode-locked (ML) regimes. A maximum output power of 524 mW is obtained in the CW regime with a 5% output coupler at an absorbed pump power of 2.04 W, corresponding to a slope efficiency of 27.9%. A maximum CW wavelength tuning range of 160 nm at the zero level, from 1984 to 2144 nm, is obtained with a 0.2% output coupler. In the ML regime, pumping with 5.5 W (unpolarized), the average output power (0.2% output coupler) reaches 148 mW at a repetition rate of ~96 MHz. The output spectrum is centered at 2071.5 nm with a FWHM of 21.5 nm (σ-polarization). The pulse duration amounts to 218 fs (time-bandwidth product equal to 0.327).

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