Skip to content

Channel waveguide lasers in bulk Tm -LiYF4 produced by deep diamond-saw dicing

MetadataDetails
Publication Date2020-07-26
JournalOptics Express
AuthorsPavel Loiko, Ludovic Gauthier‐Manuel, Gurvan Brasse, Esrom Kifle, Lauren Guillemot
InstitutionsUniversité Marie et Louis Pasteur, Centre de Recherche sur les Ions, les Matériaux et la Photonique
Citations8

We report on a novel approach to fabricate channel (ridge) waveguides (WGs) in bulk crystals using precision diamond saw dicing. The channels feature a high depth-to-width aspect ratio (deep dicing). The proof-of-the-concept is shown for a Tm 3+ :LiYF 4 fluoride crystal. Channels with a depth of 200 ”m and widths of 10-50 ”m are diced and characterized by confocal laser microscopy revealing a r.m.s. roughness of the walls well below 100 nm. The channels obtained possess waveguiding properties at ∌815 nm with almost no leakage of the guided mode having a vertical stripe intensity profile into the bulk crystal volume and relatively low propagation losses (0.20-0.43 dB/cm). Laser operation is achieved in quasi-CW regime by pumping at 780 nm. The maximum peak output power reaches 0.68 W at ∌1.91 ”m with a slope efficiency of 53.3% (in σ-polarization). The proposed concept is applicable to a variety of laser crystals with different rare-earth dopants.