RU2548634C1 - Luminescing glass - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: glass containing B₂O₃, Al₂O₃, La₂O₃ and/or Y₂O₃ and Yb₂O₃, has the following relative content of components, mol %: 57-62 B₂O₃, 27-33 Al₂O₃, 1-9.5 La₂O₃ and/or Y₂O₃, 0.5-10 Yb₂O₃.

EFFECT: creation of glass characterized by intensive broadband luminescence in near infrared area of spectrum and suitable for use as the active medium of laser.

1 tbl, 1 dwg

Description

The invention relates to optical materials, in particular to compositions of Yb-containing optical glasses, which can be used as active media of lasers (including fiber), generating in the near infrared region of the spectrum.

Known ytterbium phosphate glass composition, mol. %: 60-75 P ₂ O ₅ , 10-30 Yb ₂ O ₃ , 0-30 combination of two or more components X ₂ O ₃ , R ₂ O, MO; here X ₂ O ₃ represents 0-26 mol. %, and X is selected from Al, B, La, Sc, Y and mixtures thereof; R ₂ O represents 0-26 mol%, and R is selected from Li, Na, K and mixtures thereof; MO represents 0-26 mol%, and M is selected from Mg, Ca, Sr, Ba, Zn and mixtures thereof (Ytterbium-phosphate glass, US Pat. No. 7,531,473 B2).

The disadvantages of the known glass are low moisture resistance and heat resistance, as well as high losses on the cooperative luminescence of Yb ³⁺ ions, which complicates its use in the field and prevents obtaining efficient generation at a high level of pumping.

Known glass composition, mol.%: 22 MgF ₂ , 32-52 BaF ₂ , 5-25 PbF ₂ , 20 Al (PO ₃ ) ₃ , 1 YbF ₃ (Yb ³⁺ doped fluorine phosphorous glass with high crystallization stability and preparing method thereof, patent CN 101269913 (A) from 2008-09-24).

The main disadvantage of the known glass is the low concentration of Yb ³⁺ ions, which does not allow to obtain a high specific power generation.

Known luminescent germanate glass composition, mol.%: (40-60) GeO ₂ , (0,01-5) Er ₂ O ₃ , (1-28) Yb ₂ O ₃ , (15-30) B ₂ O ₃ , (1-5) Al ₂ O ₃ , (1-25) La ₂ O ₃ (Luminescent germanate glass, patent RB No. 12472, patent of the Russian Federation No. 2383503).

A disadvantage of the known glass is the difficulty of generating generation on Yb ³⁺ ions due to the transfer of excitations from them to Er ³⁺ ions.

Known luminescent quartz glass composition, wt.%: (88-96) SiO ₂ , (3-9) Yb ₂ O ₃ , (1-3) Rb ₂ O according to paragraph 1 and (87-95) SiO ₂ , (3 -9) Yb ₂ O ₃ , (1-2) Rb ₂ O, (1-2) Cs ₂ O according to paragraph 2 (Luminescent quartz glass (options), patent RB No. 16901, patent of the Russian Federation No. 2482079).

A disadvantage of the known glass is the relatively high intensity of cooperative luminescence of Yb ³⁺ ions (λ≈500 nm), which prevents the generation of efficient lasing at a high pump level.

Closest to the claimed glass according to the technical nature is glass composition, mol.%: (65-73) B ₂ O ₃ , (15-20) Al ₂ O ₃ , (8-15) La ₂ O ₃ or Y ₂ O ₃ , (0.1-4) Sm ₂ O ₃ (Luminescent glass, patent of RB No. 14839, patent of the Russian Federation No. 2415089).

The disadvantage of the prototype is the inability to obtain generation of a near infrared region because of small branching coefficient luminescence in the transitions _5-2 ⁴ G → ⁶ F _{3/2 → 11/2} ions Sm ³⁺ (λ≈940-1500 nm) and overlapping respective bands with absorption bands of these ions. This does not allow using the prototype as active media of lasers generating in the near infrared region of the spectrum.

The objective of the invention is the creation of luminescent glass, characterized by intense broadband luminescence in the near infrared region of the spectrum and suitable for use as an active medium of a laser.

To solve this problem, luminescent glass containing oxides of boron (B ₂ O ₃ ), aluminum (Al ₂ O ₃ ) and lanthanum (La ₂ O ₃ ) and / or yttrium (Y ₂ O ₃ ), additionally contains ytterbium oxide (Yb ₂ O ₃ ) in the following ratio of components, mol%: (57-62) B ₂ O ₃ , (27-33) Al ₂ O ₃ , (1-9,5) La ₂ O ₃ and / or Y ₂ O ₃ , (0.5-10) Yb ₂ O ₃ .

The starting materials were mixed in the required ratio, and the resulting mixture was melted in air in a platinum crucible for 1 hour. The development was carried out by casting the melt onto a metal plate.

A decrease in the concentration of Yb ₂ O ₃ below the claimed is impractical due to the low intensity of luminescence. An increase in the concentration of Yb ₂ O _{3 in} excess of the claimed is impractical due to a decrease in the quantum yield of luminescence. A change in the concentration of the remaining ingredients within the claimed limits, including the replacement of La ₂ O ₃ with Y ₂ O ₃ , weakly affects the spectrum and quantum yield of luminescence of the claimed glass.

ионов Yb³⁺, и квантового выхода люминесценции последних η=τ/τ₀ сведены в таблицу. Здесь I - интенсивность люминесценции, τ₀ - радиационное время жизни метастабильного состояния Yb³⁺, определяемое по известной формуле

где g - статистический вес энергетического состояния, n - показатель преломления стекла (определялся иммерсионным методом). При определении

возбуждение осуществлялось моноимпульсным излучением лазера на сапфире с титаном (λ=900 нм, длительность импульса ≈10 нс), регистрация производилась при λ=976 нм, толщина образцов составляла 1 мм.The compositions of the claimed glass and the absorption coefficient k at the maximum of a purely electronic transition (λ≈976 nm), the average duration of the luminescence decay

ions Yb ³⁺ , and the quantum yield of the luminescence of the latter η = τ / τ ₀ are tabulated. Here I is the luminescence intensity, τ ₀ is the radiation lifetime of the metastable state of Yb ³⁺ , determined by the well-known formula

where g is the statistical weight of the energy state, n is the refractive index of the glass (determined by the immersion method). In determining

The excitation was carried out by single-pulse radiation of a sapphire laser with titanium (λ = 900 nm, pulse duration ≈10 ns), registration was carried out at λ = 976 nm, the thickness of the samples was 1 mm.

Table Sample No. Composition, mol.% k, cm ^-1

, мкс $$\overline{\tau }$$

μs η,% B ₂ O ₃ Al ₂ O ₃ La ₂ O ₃ and / or Y ₂ O ₃ Yb ₂ o ₃ one 57 33 9.5 0.5 3,7 920 ≈100 2 60 thirty 9 one 6.7 940 ≈100 3 60 thirty 5 5 25.3 360 ≥40 four 62 27 one 10 48.0 220 ≥25

The figure shows the light attenuation spectrum (curve 1) and the "quantum" luminescence spectrum at an excitation wavelength of 900 nm (curve 2) for sample No. 2.

It is seen that the quantum yield of luminescence of the inventive glass at Yb ₂ O ₃ concentrations less than or equal to 1 mol.% Is close to 100% and remains quite high (≥40%) at an activator oxide concentration of 5 mol.%. A distinctive feature of this glass is the low intensity of cooperative luminescence of Yb ³⁺ ions. For example, compared with the considered analogue (patents of the Republic of Belarus No. 16901 and the Russian Federation No. 2482079), it is at least two orders of magnitude lower. The inventive glass is resistant to damp atmosphere and staining agents.

Thus, the claimed glass in contrast to the prototype is characterized by effective broadband luminescence in the near infrared region of the spectrum. Due to the low efficiency of cooperative luminescence of Yb ³⁺ ions, it is promising for use in conditions of high population of the metastable state of the activator. This provides the claimed glass advantage in the quality of the active element of the near-infrared lasers operating in monopulse mode.

Claims (1)

Luminescent glass containing oxides of boron (B ₂ O ₃ ), aluminum (Al ₂ O ₃ ) and lanthanum (La ₂ O ₃ ) and / or yttrium (Y ₂ O ₃ ), characterized in that it further comprises ytterbium oxide (Yb ₂ O ₃ ) in the following ratio of components, mol.%:
B ₂ O ₃ 57-62 Al ₂ O ₃ 27-33 La ₂ O ₃ and / or Y ₂ O ₃ 1-9.5 Yb ₂ o ₃ 0.5-10

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