Er<3+>/Yb<3+> co-doped yttrium lithium fluoride monocrystal and preparation method thereof

Abstract

The invention discloses an Er<3+>/Yb<3+> co-doped yttrium lithium fluoride monocrystal and a preparation method thereof. The yttrium lithium fluoride monocrystal is a rare earth ion Er<3+>/Yb<3+> co-doped monocrystal; the molecular formula is LiY(1-x-y)ErxYbyF4, wherein x is greater than or equal to 0.008 and less than or equal to 0.085, and y is greater than or equal to 0.002 and less than or equal to 0.170; the segregation coefficients of Yb<3+> and Er<3+> in the yttrium lithium fluoride are about 1, and efficient intermediate infrared laser of 2.7 microns can be output; and the yttrium lithium fluoride monocrystal has high transmittance of intermediate infrared laser, has better thermal, mechanical and chemical stabilities than those of glass state materials and has the characteristics of low phonon energy, high optical transmittance of wavebands with width of 300-5500nm, less color center forming amount, low thermal lens effect and the like, thereby being more easily processed and more suitably used in laser devices. In the preparation method disclosed by the invention, a sealing crucible falling technology is used, so that the operation is simple; the raw material is fluorated at high temperature in a sealed water-free and oxygen-free environment, so that the crystal is isolated from air and water vapor during the growth; and therefore, the high-quality Er<3+>/Yb<3+> co-doped LiYF4 monocrystal containing little OH<-> ion and oxide is obtained.

Description

technical field [0001] The invention relates to yttrium lithium fluoride crystals, in particular to an Er crystal with enhanced emission characteristics in the 2.7 μm mid-infrared band 3+ / Yb 3+ Co-doped yttrium lithium fluoride single crystal and its preparation method. Background technique [0002] In recent years, due to its important applications in laser medical surgery, remote sensing, lidar, chemical sensing, air pollution control, communications and military, solid-state lasers in the mid-infrared 2.7μm central band have been highly valued by research institutions at home and abroad. [0003] Inorganic materials doped with rare earth ions are one of the effective ways to obtain near-infrared and mid-infrared lasers. Most lanthanide rare earth ions have abundant energy level structures. Among them Er 3+ rare earth ion 4 I 11 / 2 → 4 I 13 / 2 The energy level jump can produce 2.7μm fluorescence emission, with Er 3+ The 2.7μm mid-infrared laser materials with lumin...

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Problems solved by technology

[0004] Er 3+ the upper level of the ion 4 I 11 / 2 The fluorescence lifetime is lower than the energy level 4 I 13 / 2 short, so Er 3+ Ion single-doped crystals have relatively low luminous efficiency and weak luminous intensity in the 2.7 μm band, which will seriously restrict the application of this type of material in the 2.7 μm band mid-infrared lasers

[0005] Although the Er 3+ The 2.7μm mid-infrared enhanced luminescence effect of ions, but for germanate oxide glass materials, it is difficult to solve the problem of high-quality large-scale glass preparation, especially the poor mechanical properties, thermal properties, physical and chemical properties and mechanical strength of glass materials. The inherent defects and technical difficulties restrict its development, and also become the biggest obstacle to the practical application of non-oxide glass optical fibers such as special fluorides

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