Femtosecond-laser-written hexagonal cladding waveguide in Tm:KLu(WO_4)_2: µ-Raman study and laser operation

We report on the fabrication, µ-Raman characterization, and continuous-wave laser operation of a channel waveguide with a hexagonal optical-lattice-like cladding fabricated in monoclinic Tm:KLu(WO4)2 crystal by femtosecond direct laser writing. µ-Raman spectroscopy indicates preservation of the crys...

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Detalhes bibliográficos
Autores: Kifle, Esrom, Loiko, Pavel, Mateos, Xavier, Vázquez de Aldana, Javier R., Ródenas, Airan, Griebner, Uwe, Petrov, Valentin, Aguiló, Magdalena, Díaz, Francesc
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Recursos:Universidad de Salamanca (USAL)
Repositorio:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/146858
Acesso em linha:http://hdl.handle.net/10366/146858
Access Level:acceso abierto
Palavra-chave:Channeled waveguides
Femtosecond laser writing
Laser beams
Laser modes
Laser operation
Waveguide lasers
Descrição
Resumo:We report on the fabrication, µ-Raman characterization, and continuous-wave laser operation of a channel waveguide with a hexagonal optical-lattice-like cladding fabricated in monoclinic Tm:KLu(WO4)2 crystal by femtosecond direct laser writing. µ-Raman spectroscopy indicates preservation of the crystalline quality in the core region and an anisotropic residual stress field. When pumped by a Ti:Sapphire laser at 802 nm, the Tm:KLu(WO4)2 buried channel waveguide laser generated 136 mW at 1843.7 nm with a slope efficiency of 34.2% and a threshold as low as 21 mW, which are the record characteristics for femtosecond-laser-written Tm crystalline waveguide lasers. The variation of the output coupling resulted in discrete wavelength tuning of the laser emission from 1785 to 1862 nm. The propagation losses in the waveguide are ~1.2 ± 0.3 dB/cm.