Open AccessStudy on the dopant concentration ratio in thulium-holmium doped silica fibers for lasing at 2.1µm
Author(s) -
N. J. Ramírez-Martínez,
M. Núñez-Velázquez,
J.K. Sahu
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.397855
Subject(s) - thulium , materials science , holmium , slope efficiency , lasing threshold , doping , laser , fiber laser , optics , fabrication , cladding (metalworking) , optoelectronics , composite material , wavelength , medicine , physics , alternative medicine , pathology
We present the fabrication and laser performance of thulium-holmium co-doped silica fibers when cladding pumped at ∼790 nm. By using the hybrid gas phase-solution doping process in conjunction with the MCVD preform fabrication technique, the doping concentration and the Tm:Ho ratio were varied to study the energy transfer efficiency from Tm 3+ to Ho 3+ . Our study indicates that for a thulium concentration that has resulted in an efficient two-for-one cross- relaxation process with 790 nm pumping, and while maintaining a Tm:Ho concentration ratio in the range ∼ 10 to 20, the energy transfer efficiency has reached above 75%. In a free-running laser cavity, the pump power limited laser output of 38W with a slope efficiency of 56% at 2.1 microns is demonstrated.