CN101182121B - Bismuth-nickel co-doped transparent silicate glass-ceramics and preparation method thereof - Google Patents

Abstract

A bismuth-nickel co-doped transparent silicate glass-ceramics and a preparation method thereof. The glass has the following components and molar percentages: _SiO2 (45-55), _Al2O3 (10-20), _Ga2O3 (5-20), _MgO (15-25), _TiO2 (5-10), NiO (0.005-1), _{and Bi2O3} (0.005-2). The near-infrared fluorescence intensity _of nickel in the bismuth-nickel co-doped transparent silicate glass-ceramics obtained by bismuth-nickel co-doping can be increased by up to about 4.4 times, and the fluorescence lifetime can be increased from 210 microseconds of single nickel doping to 350 microseconds of co-doping, so that the bismuth-nickel co-doped transparent glass-ceramics is expected to be applied in the fields of broadband optical amplifiers, high-power lasers, tunable lasers, etc.

Description

Bismuth-nickel co-doped transparent silicate glass-ceramics and preparation method thereof

technical field

The invention relates to optical glass, in particular to a bismuth-nickel co-doped transparent silicate glass-ceramic and a preparation method thereof. The transparent glass-ceramics can produce stronger fluorescence in the near-infrared communication band than the transparent glass-ceramics doped with single nickel (abbreviated as Ni) when pumped by a 980nm light source. It has a long fluorescence lifetime and a wide gain bandwidth, and is suitable for As a gain medium for broadband optical amplifiers and lasers.

Background technique

In recent years, with the rapid development of computer networks and other new data transmission services, the demand for communication capacity of long-distance optical fiber transmission systems has expanded rapidly. How to further improve the communication capacity of the existing optical fiber transmission system to meet the growing demand has become a research hotspot in the field of optical communication. It has been widely believed that increasing the gain bandwidth and flatness of fiber amplifiers in fiber optic transmission systems is the most effective way to increase fiber transmission capacity. However, the gain bandwidth of the practical erbium-doped fiber amplifier is difficult to be broadened, because the bandwidth of the rare earth ion 4f-4f optical transition is narrow in nature, so the optical amplifier bandwidth caused by a rare earth ion doping The extension is limited. The same problem also occurs with thulium, praseodymium, samarium and other rare earth ions. Fiber Raman amplifiers (FRAs) can achieve wide-band amplification in a wide range, but they require multi-band pumps and have low gain efficiency, and the structure of broadband fiber Raman amplifiers is complex, requiring extremely high-power pump lasers, and consumes a lot of energy. . Therefore, if an ultra-broadband optical amplifier with high gain and covering the entire communication window can be developed, it is possible to simultaneously amplify the optical signal of the entire communication window with only one optical amplifier, which will cause a leap in the field of optical communication. The progress of optical communication promotes the development of all-optical communication network.

Transition metal nickel ions (Ni ²⁺ ) have long been used as active ions in crystal materials. Under pumping by a 980nm light source, it can emit light covering the entire optical communication window in the near-infrared region, and has high quantum efficiency and long lifetime. . For example, it is known that Ni ²⁺ :MgO crystals exhibit broadband luminescence at about 1.3 μm, and have achieved laser output, but nickel-doped crystals are difficult to draw into optical fibers, which limits their wide-band optical amplification and tunable Laser applications. However, Ni ²⁺ doped glass has only weak infrared luminescence at room temperature, and even no luminescence in some glasses, because the non-radiative transition process of Ni ²⁺ dominates in the amorphous environment. Transparent glass-ceramics is expected to be the carrier of Ni, because it can be easily made into various shapes like glass, and the nanocrystals in the glass-ceramics can be used as the activator of Ni ²⁺ ions, so as to achieve high Ni-doped crystals. quantum efficiency and long-lived broadband infrared luminescence.

However, compared with crystals, the doping concentration of nickel in glass-ceramics is very low, resulting in weak absorption in the near-infrared region, which greatly reduces its pumping efficiency and infrared luminescence properties. Based on the principle of sensitized luminescence, if it is possible to find such a sensitized ion whose emission under 980nm laser pumping has a good spectral overlap with the near-infrared absorption of Ni ²⁺ ions in glass ceramics, then it is possible Enhancing the infrared luminescent properties of Ni ²⁺ through energy transfer.

Contents of the invention

The purpose of the present invention is to improve the Ni ²⁺ ion spectral properties in transparent glass-ceramics, propose a kind of bismuth-nickel co-doped transparent silicate glass-ceramics and its preparation method, through the energy transfer of bismuth to nickel to enhance the material Luminous properties. Through the co-doping of bismuth, the near-infrared fluorescence intensity of nickel can be increased by up to about 4.4 times, and the fluorescence lifetime can be increased from 210 microseconds of single-doped nickel to 350 microseconds of co-doped, making this bismuth-nickel co-doped transparent micro Crystal glass is expected to be applied in broadband optical amplifiers, high-power lasers, tunable lasers and other fields.

Technical solution of the present invention is as follows:

A bismuth-nickel co-doped transparent silicate glass-ceramic, the composition and molar percentage of raw materials used in the glass are as follows:

Composition mol%

SiO ₂ 45～55

Al ₂ O ₃ 10～20

Ga ₂ O ₃ 5～20

MgO 15～25

TiO ₂ 5～10

NiO 0.005～1

Bi ₂ O ₃ 0.005～2

The preparation method of described bismuth-nickel co-doped transparent silicate glass-ceramics comprises the following steps:

(1) Select the composition and mole percentage of the glass, weigh each raw material of a certain total amount according to the proportioning ratio, and grind for 10 to 60 minutes in an agate mortar;

(2) Put the ground raw material into a platinum crucible, melt it at 1500-1650°C, and keep it for 1-10 hours;

(3) Pouring the glass melt on a stainless steel plate, and lightly flatten it with another steel plate, then transfer it to the muffle furnace for annealing at 550-700°C, hold the temperature for 0.5-10 hours, and then turn off the power of the muffle furnace Let the glass drop to room temperature with the furnace, take it out and get transparent glass;

(4) According to the results of differential thermal analysis of the glass, raise the temperature from room temperature to 800-950°C at a rate of 300°C/hour, and keep it warm for 1-20 hours; or adopt two-step heat treatment: first, heat up at 300°C/h Raise the temperature from room temperature to 700-750°C, keep it warm for 2-20 hours, then raise it to 800-950°C at the same rate, keep it warm for 1-20 hours, then turn off the power of the muffle furnace, let the glass cool down to room temperature with the furnace , take it out to get transparent glass-ceramics.

Experiments show that the color of the glass and glass-ceramic of the present invention varies with the doping concentration of NiO and Bi ₂ O ₃ (see Table 1); all glass and glass-ceramic samples are uniform and transparent. The crystallite phase precipitated in the glass-ceramic is MgAl ₂ O ₄ spinel solid solution, the size of which is below 7nm after being treated at 950℃ for 2 hours, and the size does not change significantly with the prolongation of heat treatment time. MgAl ₂ O ₄ spinel has tetrahedral and octahedral vacancies, in which Mg ²⁺ ions occupy one-eighth of tetrahedral vacancies, and Al ³⁺ ions occupy half of octahedral vacancies. In the transparent glass-ceramics co-doped with Bi and Ni, Ni ²⁺ ions enter the remaining octahedral vacancies and/or partially replace the Al ³⁺ ions in the octahedron to form a spinel solid solution, while Bi ions reside in the glass phase , this is because the radius of Bi ions is much larger than the size of tetrahedral and octahedral vacancies in spinel, and cannot enter spinel. Spectral testing found that the absorption of Ni ²⁺ ions ³ A ₂ ( ³ F) → ³ T ₂ ( ³ F) in the glass-ceramics had a good spectral overlap with the near-infrared emission of Bi ions pumped at 980 nm (Fig. 1), the efficient energy transfer from Bi to Ni may occur according to the principle of sensitized luminescence. Our results also prove that Bi ions do indeed undergo effective energy transfer to Ni ²⁺ ions, which greatly improves the near-infrared luminescent properties of Ni ²⁺ ions.

Experiments show that: through the co-doping of bismuth and nickel, the near-infrared fluorescence intensity of nickel can be increased by about 4.4 times, and the fluorescence lifetime can be increased from 210 microseconds of single-doping nickel to 350 microseconds of co-doping, making this bismuth-nickel co-doping The doped transparent glass-ceramic is expected to be applied in broadband optical amplifier, high-power laser, tunable laser and other fields.

Description of drawings

Fig. 1 is the emission spectrum (curve 1, excited by a 980nm laser diode) of the glass-ceramic of Comparative Example 2 of the present invention and the absorption spectrum (curve 2) of the glass-ceramic of Comparative Example 3.

Fig. 2 is the emission spectrum (980nm laser diode excitation) of the glass-ceramics of Comparative Example 3 and Examples 4-7 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but the protection scope of the present invention should not be limited thereby.

Table 1 has listed the compositions and molar percentages thereof of eleven embodiments of the glass of the present invention, the color of the corresponding glass, the heat treatment system, the color of the glass-ceramic, the fluorescence peak position of the glass-ceramic under the excitation of 980nm pump light, Test results of full width at half maximum and lifetime are also listed therein, wherein Examples 2 and 3 are comparative examples.

Example 1

This example is only doped with trace amounts of NiO and Bi ₂ O ₃ . The preparation method of transparent glass-ceramics is as follows: Weigh approximately 50 g of raw materials according to the composition ratio of Example 1, grind them in an agate mortar for 30 minutes, and then place them in a platinum crucible and melt them at 1550° C. for 2 hours; the glass melt rapidly Cast on a stainless steel plate, and lightly flatten it with another steel plate, then transfer it to a muffle furnace for annealing at 650°C for 2 hours, then turn off the power of the muffle furnace and let the glass drop to room temperature with the furnace, and take it out to get a nearly colorless glass Transparent glass. Put the transparent glass sample into the muffle furnace and raise it from room temperature to 950°C at a rate of 300°C/h, keep it warm for 2 hours, then turn off the power of the muffle furnace and let the glass sample drop to room temperature with the furnace, and take it out to get a transparent glass sample. Crystal glass, almost colorless. The glass-ceramic samples were processed into 7×7×2mm ³ and polished for testing. Due to the low doping concentration, the 980nm laser diode pumps only weak near-infrared luminescence from Ni ²⁺ ions, with a full width at half maximum of about 124nm and a lifetime of about 62 microseconds at room temperature.

Comparative Examples 2 and 3

Comparative Examples 2 and 3 were monodoped with Bi ₂ O ₃ and NiO, respectively. The preparation method of transparent glass-ceramics is as follows: Weigh about 50 g of raw materials according to the composition ratio of Comparative Examples 2 and 3, grind them in an agate mortar for 30 minutes, and then place them in a platinum crucible and melt them at 1550° C. for 2 hours; The molten glass is quickly poured on a stainless steel plate, and lightly flattened with another steel plate, then transferred to the muffle furnace and annealed at 650°C for 2 hours, then turn off the power of the muffle furnace and allow the glass to cool down to room temperature with the furnace, then take it out. Transparent glass. The glass of Comparative Example 2 is pink, and the glass of Comparative Example 3 is brownish yellow. Put the transparent glass sample into the muffle furnace and raise it from room temperature to 950°C at a rate of 300°C/h, keep it warm for 2 hours, then turn off the power of the muffle furnace and let the glass sample drop to room temperature with the furnace, and take it out to get a transparent glass sample. crystal glass. The glass-ceramic of Comparative Example 2 is ocher, and the glass-ceramic of Comparative Example 3 is light sea blue. The glass-ceramic samples were processed into 7×7×2mm ³ and polished for testing. Fig. 1 is the emission (excited at 980nm) of comparative example 2 glass-ceramics and the absorption spectrum of comparative example 3 glass-ceramics, it can be seen that in the glass-ceramics Bi ion center is at the emission spectrum of 1137nm and Ni ²⁺ ion center is at The absorption spectra at 1000 nm partially overlap, so there is a possibility of energy transfer from Bi ions to Ni ²⁺ ions. The fluorescence spectrum of the glass-ceramics of Comparative Example 3 under 980nm pumping is shown in Figure 2, the fluorescence peak is at 1240nm, the fluorescence half-maximum width is about 262nm, and the lifetime at room temperature is about 210 microseconds.

Example 4-7

The four examples have similar compositions, doped with different amounts of Bi ₂ O ₃ , and the content of NiO is fixed at 0.3 mol%. The preparation method of transparent glass-ceramics is as follows: Weigh about 50 g of raw materials according to the composition ratio of the four examples, grind them in an agate mortar for 30 minutes, then place them in a platinum crucible and melt them at 1550°C for 2 hours; Quickly pour the liquid on a stainless steel plate, and lightly flatten it with another steel plate, then transfer it to a muffle furnace and anneal at 650°C for 2 hours, then turn off the power of the muffle furnace and let the glass drop to room temperature with the furnace, and take it out to get a transparent glass , are brown-yellow. Put the transparent glass sample into the muffle furnace and raise it from room temperature to 950°C at a rate of 300°C/h, keep it warm for 2 hours, then turn off the power of the muffle furnace and let the glass sample drop to room temperature with the furnace, and take it out to get a transparent glass sample. Crystal glass, the glass-ceramic of embodiment 4 is light ochre, and all the other three are ochre. The glass-ceramic samples were processed into 7×7×2mm ³ and polished for testing. The fluorescence spectrum of glass ceramics is shown in Figure 2. It can be seen that the fluorescence intensity of Ni ₂₊ ions increases continuously with the increase of _Bi2O3 concentration, and the fluorescence intensity begins to decrease when the _Bi2O3 concentration ^exceeds _0.75mol %. . Compared with the fluorescence intensity of the single-doped NiO glass-ceramic in Comparative Example 3, the fluorescence intensity of Examples 4, 5, 6 and 7 was respectively enhanced by about 2.2, 3.4, 4.4 and 3.1 times, and the fluorescence half-maximum width did not change much. The fluorescence lifetime was increased by about 40 to 140 microseconds.

Examples 8-11

The four examples are doped with higher levels of NiO and Bi ₂ O ₃ . The preparation method of transparent glass-ceramics is as follows: Weigh about 50 g of raw materials according to the composition ratio of the above four examples, grind them in an agate mortar for 30 minutes, and then place them in a platinum crucible and melt them at 1580°C for 2 hours; The melt is quickly poured on a stainless steel plate, and lightly flattened with another steel plate, then transferred to the muffle furnace and annealed at 650°C for 2 hours, then turn off the power of the muffle furnace and let the glass cool down to room temperature with the furnace, and it will become transparent after taking it out Glass; the glass of Example 8 is brownish yellow, and the other three are brown. Put the transparent glass sample into the muffle furnace and raise it from room temperature to 950°C at a rate of 300°C/h, keep it warm for 2 hours, then turn off the power of the muffle furnace and let the glass sample drop to room temperature with the furnace, and take it out to get a transparent glass sample. crystal glass. The glass-ceramic of Example 8 is ocher, and the glass-ceramics of the remaining three examples are dark ocher. The glass-ceramic samples were processed into 7×7×2mm ³ and polished for testing. Due to the high doping concentration of NiO and _Bi2O3 , the concentration quenching between Ni2 ⁺ ions and the cross relaxation between Ni2 ⁺ ions and Bi _ions greatly reduce the fluorescence intensity of Ni2 ⁺ ions, while The fluorescence lifetime is also greatly shortened, while the fluorescence peak position gradually red shifts with the increase of NiO concentration, and the fluorescence half maximum width gradually increases with the NiO concentration, as shown in Table 1.

Table 1

Example serial number 1 2 3 4 5 SiO₂Al₂O₃Ga₂O₃MgOTiO₂NiOBi₂O₃Glass Color Heat Treatment System (°C-h) Glass-ceramics Color Microcrystalline Phase Fluorescence Peak Position (nm) Fluorescence FWHM (nm ) Fluorescence lifetime^*(μs) 4510202050.0050.005 approximately colorless 950-2 approximately colorless MgAl₂O₄119012462 481511251000.75 pink 950-2 ocher MgAl₂O₄1137191285 5016.58.316.68.30.30 Brown Yellow 950-2 Light Sea Blue MgAl₂O₄1240262210 5016.58.316.58.150.30.25 brownish yellow 950-2 light ocher MgAl₂O₄1240270250 5016.48.316.48.10.30.5 brown yellow 950-2 ocher MgAl₂O₄1240271312

^* 980nm semiconductor diode pumped

Continued Table 1

6 7 8 9 10 11 5016.38.1516.38.20.30.75 brown yellow 950-2 ocher MgAl₂O₄1240264350 5016.28.116.28.20.31 brownish yellow 950-2 ocher MgAl₂O₄1240272313 52205156.250.51.25 brownish yellow 950-2 ocher MgAl₂O₄1260286235 5318714.55.30.71.5 brown 950-2 dark ocher MgAl₂O₄1296302168 541210165.2511.75 brown 950-2 dark ocher MgAl₂O₄1328315110 5512815712 Brown 950-2 Dark Ocher MgAl₂O₄132832094

Claims (2)

1. bismuth-nickel co-doped transparent silicate glass-ceramics is characterized in that composition and molar percentage that this glass is raw materials used are as follows:

Ingredient m ol%

SiO ₂ 45～55

Al ₂O ₃ 10～20

Ga ₂O ₃ 5～20

MgO 15～25

TiO ₂ 5～10

NiO 0.005～1

Bi ₂O ₃0.005～2, the preparation method of this glass is as follows:

(1) composition and the molar percentage of selected glass, each raw material by the certain total amount of this proportioning weighing ground in agate mortar 10～60 minutes;

(2) ground raw material is put into Platinum crucible, melt soaking time 1～10 hour in 1500～1650 ℃;

(3) glass melt is cast on the stainless-steel sheet, and gently flattens, change over to afterwards in the retort furnace and under 550～700 ℃, anneal with another steel plate, soaking time 0.5～10 hour, close the retort furnace power supply then, allow glass reduce to room temperature, take out and promptly get transparent glass with stove;

(4) according to the DTA on Glass result, be raised to 800～950 ℃ with 300 ℃/hour temperature rise rates from room temperature, be incubated 1～20 hour; Perhaps adopt two step thermal treatments: the temperature rise rate with 300 ℃/h is raised to 700～750 ℃ from room temperature earlier, be incubated 2～20 hours, be raised to 800～950 ℃ with same temperature rise rate again, be incubated 1～20 hour, close the retort furnace power supply then, allow the glass furnace cooling to room temperature, taking-up can obtain transparent glass-ceramics.

2. the concrete preparation method of the described bismuth-nickel co-doped transparent silicate glass-ceramics of claim 1 is characterised in that to comprise the following steps:

(1) composition and the molar percentage of selected glass, each raw material by the certain total amount of this proportioning weighing ground in agate mortar 10～60 minutes;

(2) ground raw material is put into Platinum crucible, melt soaking time 1～10 hour in 1500～1650 ℃;

(3) glass melt is cast on the stainless-steel sheet, and gently flattens, change over to afterwards in the retort furnace and under 550～700 ℃, anneal with another steel plate, soaking time 0.5～10 hour, close the retort furnace power supply then, allow glass reduce to room temperature, take out and promptly get transparent glass with stove;

(4) according to the DTA on Glass result, be raised to 800～950 ℃ with 300 ℃/hour temperature rise rates from room temperature, be incubated 1～20 hour; Perhaps adopt two step thermal treatments: the temperature rise rate with 300 ℃/h is raised to 700～750 ℃ from room temperature earlier, be incubated 2～20 hours, be raised to 800～950 ℃ with same temperature rise rate again, be incubated 1～20 hour, close the retort furnace power supply then, allow the glass furnace cooling to room temperature, taking-up can obtain transparent glass-ceramics.

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