title: Deactivation effects of the lowest excited state of Ho3+ at 2.9 μm emission introduced by Pr3+ ions in LiLuF4 crystal.
abstract: The use of Pr3+ codoping for enhancement of the Ho3+:5I6 →5I7 mid-IR emissions were investigated in the LiLuF4 crystal for the first time. It was found that Pr3+ greatly increased Ho3+ 2.9 μm emission by depopulating the Ho3+:5I7 level while having little influence on the Ho3+:5I6 level, leading to greater population inversion. The energy transfer efficiency from Ho3+:5I7 to Pr3+:3F2 is calculated to be 88%. Based on Judd-Ofelt theory, the 2.9 μm emission cross section is calculated to be 1.91×10(-20)   cm2, and the gain property of the Ho3+:5I6 →5I7 transition is discussed. We propose that the Ho, Pr:LiLuF4 crystal may be a promising material for 2.9 μm laser applications.
authors.affiliation: Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Peixiong
authors.initials: P
authors.lastname: Zhang
authors.forename: Yin
authors.initials: Y
authors.lastname: Hang
authors.forename: LianHan
authors.initials: L
authors.lastname: Zhang
mesh_terms: D003460:Crystallization; D005459:Fluorides / Q000737:chemistry* / Q000528:radiation effects; D006695:Holmium / Q000737:chemistry* / Q000528:radiation effects; D007477:Ions; D007834:Lasers; D018020:Lithium Compounds / Q000737:chemistry* / Q000528:radiation effects; D008187:Lutetium / Q000737:chemistry* / Q000528:radiation effects; D008422:Materials Testing; D012542:Scattering, Radiation
chemical_list: D007477:Ions; D018020:Lithium Compounds; C027651:lithium fluoride; D008187:Lutetium; D005459:Fluorides; D006695:Holmium