Abstract : By the mean of InGaAs diode, trivalent ytterbium ions can give rise to an interestinginfrared emission for laser applications. Numerous compounds are in study. Among them,borates are stable, UV-transparent compounds and they have a high damage threshold. Thusthey are good candidates for optical applications. From a structural point of view, they exhibita diversity of host sites for the rare earth which allows to modulate emission withcomposition.We carry out an elaboration and characterization study on a borate and two oxyboratecompounds of formula Li6Ln(BO3)3 ; LiGd6O5(BO3)3 ; Na3La9O3(BO3)8.Crystal growth, by Czochralski or flux method depending on the meltingcharacteristic, enable us to obtain centimetric sized crystals with large transparent areas.Ytterbium ion spectroscopy study enables us to estimate energy levels splitting and to locaterare earth ions in these matrices. Several thermal, mechanical and optical characterizations were also performed on the crystals to estimate laser parameters. Finally, first laser tests werecarried out and have shown the potentiality of these materials as amplifier media.