The two-step creation and tunable laser operation of F+3 centers in LiF crystals

Ab initio calculations of electronic and optical properties in O-doped LiF crystal

“…al [16], is used in a reciprocal space. The Li pseudopotential included 1s 2 and 2s 1 while the F pseudopotential had F 2s 2 and 2p 5 . The O pseudopotential had 2s 2 and 2p 4 .…”

“…The LiF crystal can be easily colored by ionizing radiation. The colored LiF crystal has very good optical and spectral properties and has been applied in visible color-centered lasers [1][2][3][4] and integrated optical devices [5], etc. Sometimes, some impurities are introduced into the pure LiF crystal for improving or enhancing certain properties of the uncolored or colored crystal, in particular the colored O-doped LiF crystal for stabilizing its lasing active centers [6,7].…”

Aggregate color center formation processes in lithium fluoride crystals after irradiation

“…Therefore from Eqs. (12), (13) follows n H >> n I , i.e., the concentration of interstitial fluorine atoms is much higher than the concentrations of interstitial fluoride ions. In such a case, reaction (4) for vacancy formation occurs much more efficiently than reaction (2) for generation of F 1 centers.…”

“…For example, in the literature it is assumed that generation of F 3 + centers in the postradiation period in LiF is possible as a result of two different reactions involving combination of defects: F 2 + color centers with F 1 centers, and anion vacancies v a with F 2 centers [11][12][13][14]16]. In this case, it is assumed that vacancies (in the following, by vacancies we will mean only anion vacancies) are created during irradiation of the crystal.…”

“…Applications of lithium fluoride with color centers require targeted variation and optimization of its properties and characteristics. In order to solve these problems, we need to know as much detail as possible about the color center formation processes.Processes involved in formation of radiation-induced color centers in lithium fluoride have been studied for many years [11][12][13][14][15][16]. It has been found that the kinetics and results of coloring LiF depend on a number of factors: the type of ionizing radiation, the irradiation dose and irradiation conditions, the chemical purity, the mechanical and thermal history of the crystal, etc.…”